Charge controlling agent containing polyhydroxyalkanoate containing unit containing carboxyl group on side chain in molecule, toner binder and toner, and image formation method and image forming apparatus using toner

ABSTRACT

The present invention provides a negataively chargeable charge controlling agent to control a charged state of a powder or granular material such as toner for electrophotography, where the agent comprises a polyhydroxyalkanoate having at least one kind of 3-hydroxy-ω-carboxyalkanoic acid unit represented by the chemical formula (1):  
                 
 
wherein n is an integer selected from 1 to 8; R 1  is an H, Na or K atom, or  
                 
 
and when more than one unit exists, n and R 1  is the same or different between the units. The charge controlling agent is excellent in electrophtographic properties and propitious to environment because of the biodegradability of the polyhydroxyalkanoate.  
                 
 
wherein n is an integer selected from the range shown in the same chemical formula; R 1  is an H atom, Na atom, K atom, or  
                 
 
and when more than one unit exists, n and R 1  may differ from unit to unit.

TECHNICAL FEILD

The present invention relates to a charge controlling agent for use inelectrophotography, electrostatic recording, magnetic recording and thelike, a toner binder, an electrostatic latent image developing toner, animage formation method using the toner, and an image forming apparatusfor use therein. In particular, the present invention relates to acharge controlling agent, a toner binder, a toner for developingelectrostatic charge images used in electrophotography, electrostaticrecording, and electrostatic printing with a copier, printer, and fax,in which a toner image is formed on an electrostatic latent imagecarrier (hereinafter simply referred to as image carrier) and then thetoner image is transferred onto an object transfer material to form animage, and an image forming method and an image forming apparatus usingthe toner. More particularly, the present invention relates to anegative charge controlling agent safer for human bodies/environments, atoner binder and a toner for developing electrostatic charge imagesusing the negative charge controlling agent, and an image forming methodand an image forming apparatus for the method using the toner.

BACKGROUND ART

So far, many methods have been known for electrophotography, and thosemethods are generally carried out in such a manner that an electriclatent image is formed on an image carrier (photosensitive member) by avariety of means using a photoconductive substance, the latent image isthen developed with a toner to form a visible image, and the toner imageis transferred onto an object transfer material such as a paper asnecessary, followed by fixing the toner image on the object transfermaterial by heat and/or pressure or the like to obtain a copy. For themethod for visualizing the electric latent image, a cascade developmentmethod, a magnetic brush development method, a pressurizing developmentmethod and the like are known. Further, a method using a magnetic tonerand a rotary development sleeve with a magnetic pole placed at thecenter thereof, where the magnetic toner is caused to fly from thedevelopment sleeve onto the photosensitive member by a magnetic field isalso used.

Development systems for use in development of an electrostatic latentimage include a two-component development system using a two-componenttype developer constituted by a toner and a carrier, and a one-componentdevelopment system using a one-component type developer constituted onlyby a toner and using no carrier.

Here, the colored fine particle generally called as a toner has a binderresin and a coloring material as essential components, and in additionthereto, magnetic powders and the like if necessary. For the method forimparting an electric charge to the toner, the electrifiability(chargeability) of the binder resin itself may be used without using acharge controlling agent, but by this method, charge stability with timeand humidity resistance are compromised, thus making it impossible toobtain high quality images. Therefore, the charge controlling agent isusually added for the purpose of maintaining and controlling the chargeof the toner.

Charge controlling agents well known in the art today include, forexample, azo dye metal complexes, aromatic dicarboxylic acid-metalcomplexes and salicylic acid derivative-metal complexes as negativefriction charging agents. In addition, as positive friction chargingagents, nigrosine-based dyes, triphenylmethane-based dyes, various typesof quaternary ammonium salts and organic tin compounds such as dibutyltin oxide are known, but toners containing these substances as thecharge controlling agent do not necessarily fully satisfy qualitycharacteristics required for the toner such as the electrifiability andstability with time depending on their compositions.

For example, a toner containing an azo dye metal complex known as anegative charge controlling agent has an acceptable charge level, butmay have reduced dispersibility depending on the type of binder resin tobe combined because the azo dye metal complex is a low-molecularcrystal. In this case, the negative charge controlling agent is notuniformly distributed in the binder resin, the charge level distributionof the obtained toner is significantly broad, and the obtained image hasa low gray-level, resulting in a poor image formation capability. Inaddition, the azo dye metal complex has a unique color tone, and is thuspresently used only for toners having limited colors around black, andif the azo dye metal complex is used as a color toner, it is a seriousproblem that it lacks clarity required for a coloring agent to obtain animage to which high level color tone is required.

In addition, examples of almost colorless negative charge controllingagents include aromatic dicarboxylic-acid metal complexes, but they maybe disadvantageous due to the fact that they are not perfectlycolorless, and that they have low dispersibility peculiar tolow-molecular-weight crystals.

On the other hand, nigrosine based dyes and triphenylmethane based dyesare presently used only for toners having limited colors around blackbecause they are colored themselves, and may be poor in time stabilityof toners in continuous copying. In addition, conventional quaternaryammonium salts may give insufficient humidity resistance when formedinto toners, and in this case, the stability with time may be so poorthat high quality images are not provided when they are repeatedly used.

In addition, in recent years, attention has been given worldwide toreduction of wastes and improvement of safety of wastes in terms ofenvironmental protection. This problem applies to the field ofelectrophotography as well. That is, as imaging apparatuses have becomewidely used, the amounts of wastes of printed papers, discarded tonersand copying papers have increased year by year, and safety of suchwastes is important from a viewpoint of protection of globalenvironment.

In the light of these problems, polymer charge controlling agents havebeen studied. Examples are the compounds disclosed in U.S. Pat. Nos.4,480,021, 4,442,189 and 4,925,765, Japanese Patent ApplicationLaid-Open Nos. 60-108861, 61-3149, 63-38958, 63-88564. Further, aspolymer charge controlling agents that allow toners to exhibitnegatively charged characteristics, copolymers of styrene and/orα-methylstyrene with alkyl(meth)acrylate ester or alkyl(meth)acrylateamide having a sulfonic acid group (Japanese Patent ApplicationLaid-Open Nos. 7-72658 and 8-179564, Japanese Patent Nos. 2114410,2623684 and 2807795) are often used. These materials offer the advantageof being colorless; however, to obtain an intended amount of charge, alarge amount of the materials needs to be added.

As described above, these compounds do not offer adequate performance ascharge controlling agents, and problems of the amount of charge, chargebuild-up characteristics, stability over time and environment stabilityarise with them. Further, taking into consideration not only thefunctions of charge controlling agents, but also their effect on thehuman body as well as the environment, charge controlling agents arestrongly wanted which can be produced using safer compounds by safer andmilder synthesis process with a reduced amount of organic solvent.

Resins that can be decomposed with time by the action of microorganismsand the like, namely biodegradable resins are under development in viewof environmental protection, and many types of microorganisms have beenreported to produce biodegradable resins having a polyester structure(polyhydroxyalkanoate: hereinafter abbreviated as PHA) and accumulatethe resin in the cell. It is known that such PHA may have variouscompositions and structures depending on the type of microorganism to beused for the production of the PHA, the culture medium composition andthe culture conditions, and hitherto studies have been conducted mainlyon control of the composition and structure of PHA to be produced interms of improvements of properties of PHA, having proven performanceparticularly in the field of medical materials. Also, in the field ofagriculture, the biodegradable resin is used in mulch films,horticulture materials, slow-releasable agricultural chemicals,fertilizers and the like. Also, in the leisure industry, thebiodegradable resin is used in fishing lines, fishing tackles, golfrequites and the like.

However, considering a wide range of application as a plastic, the abovedescribed PHAs are not fully usable in terms of their properties atpresent. For further expansion of the range of application of PHA, it isimportant to conduct a wide range of studies to improve its properties,and for this purpose, research and development of PHA having monomerunits of a variety of structures is prerequisite. On the other hand, PHAwith a substituent group introduced to the side chain is expected to bedeveloped as a “functional polymer” with very useful functions andproperties originating from the introduced substituent group byselecting the substituent to be introduced according to desiredcharacteristics and the like. That is, it is also an important challengeto conduct of development and search of excellent PHA having both suchfunctionality and biodegradability.

Application of a biodegradable resin to a binder resin particularly inproduction of toners is proposed in the field of electrophotography aswell. U.S. Pat. No. 5,004,664 discloses a toner having as itscomposition a biodegradable resin, particularly polyhydroxy butyric acidand polyhydroxy valeric acid, a copolymer thereof or a blend thereof. Inaddition, Japanese Patent Application Laid-Open No. 6-289644 disclosesan electrophotographic toner particularly for heat roll fixationcharacterized in that at least the binder resin contains a plant basedwax and a biodegradable resin, and the plant based wax is added in thebinder in an amount of 5 to 50% by weight.

In addition, Japanese Patent Application Laid-Open No. 7-120975discloses an electrophotographic toner characterized by containing alactic acid based resin as a binder resin. In addition, Japanese PatentApplication Laid-Open No. 9-274335 discloses an electrostatic latentimage developing toner characterized by containing a polyester resinobtained by dehydrating polycondensation of a composition containinglactic acid and tri- or higher functional oxycarboxylic acid and acoloring agent.

In addition, Japanese Patent Application Laid-Open No. 8-262796discloses an electrophotographic toner containing a binder resin and acoloring agent, characterized in that the binder resin is composed of abiodegradable resin, and the coloring agent is composed of non-watersoluble pigments. In addition, Japanese Patent Application Laid-Open No.9-281746 discloses an electrostatic latent image developing tonercharacterized by containing a coloring agent and an urethane-modifiedpolyester resin obtained by cross-linking polylactic acid with a tri- orhigher functional polyvalent isocyanate.

Any one of the above described electrophotographic toners contains abiodegradable resin as binder resin, and is regarded to be effective inpreservation of environments and the like.

However, reports on using a biodegradable resin in the chargecontrolling agent have not been known, and there is a room of furtherimprovement for environment preservation.

Moreover, as another technique relating to the present invention, thereis a technique relating to obtain carboxylic acid by oxidation of acarbon-carbon double bond with an oxidizing agent (Japanese PatentApplication Laid-Open No. 59-190945, J. Chem. Soc., Perkin. Trans. 1,806 (1973), Org. Synth., 4, 698 (1963), J. Org. Chem., 46, 19 (1981), J.Am. Chem. Soc., 81, 4273 (1959), Macromolecular chemistry, 4, 289-293(2001)).

DISCLOSURE OF THE INVENTION

For solving the above described problems, the present invention providesa negatively chargeable charge controlling agent being morecontributable to preservation of the environment, and having highperformance (high charge level, quick build-up of charge, excellentstability with time, and high environmental stability) and improveddispersibility. The present invention also provides a toner bindercontaining the charge controlling agent, an electrostatic latent imagedeveloping toner containing the charge controlling agent, and an imageformation method and an image forming apparatus using the electrostaticlatent image developing toner.

In order to develop a charge controlling agent contributable topreservation of environments and the like and having high performance,the inventors studied strenuously and achieved the present invention.That is, the present invention is summarized as follows.

[1] In a charge control agent for controlling a charge of powder orgranules, wherein the charge control agent comprises apolyhydroxyalkanoate having at least one kind of3-hydroxy-ω-carboxyalkanoic acid unit represented by the chemicalformula (1):

wherein n is an integer selected from the range shown in the samechemical formula; R₁ is an H, Na or K atom, or

and when more than one unit exists, n and R₁ may differ from unit tounit.[2] A toner binder used for a toner for developing electrostatic chargeimages, characterized by comprising the charge controlling agentaccording to above [1].[3] A toner for developing electrostatic charge images, characterized bycomprising at least a binder resin, a colorant and the charge controlagent according to above [1].[4] An image forming method, comprising at least a charging step ofcharging an electrostatic latent image carrier by applying voltage to acharging member from the outside; an electrostatic charge image formingstep of forming an electrostatic charge image on the chargedelectrostatic latent image carrier; a developing step of developing theelectrostatic charge image with a toner for developing electrostaticcharge images to form a toner image on the electrostatic latent imagecarrier; a transferring step of transferring the toner image on theelectrostatic latent image carrier to a recording medium; and a fixingstep of fixing the toner image on the recording medium by heat,characterized in that it uses at least a binder resin, a colorant andthe charge control agent according to above [1].[5] An image forming apparatus, comprising at least charging means ofcharging an electrostatic latent image carrier by applying voltage to acharging member from the outside; electrostatic charge image formingmeans of forming an electrostatic charge image on the chargedelectrostatic latent image carrier; developing means of developing theelectrostatic charge image with a toner for developing electrostaticcharge images to form a toner image on the electrostatic latent imagecarrier; transferring means of transferring the toner image on theelectrostatic latent image carrier to a recording medium; and fixingmeans of fixing the toner image on the recording medium by heat,characterized in that it uses at least a binder resin, a colorant andthe charge control agent according to [1].[6] A charge controlling method, characterized by comprising the stepsof preparing the charge controlling agent according to [1]; andcontrolling the charged state of a toner using the charge controllingagent.

The present invention provides a charge controlling agent using apolyhydroxyalkanoate copolymer of a monomer unit having a protected orunprotected carboxyl group at the end of the side chain andhydroxyalkanoate units having a substituent group other than straightchain alkyl groups introduced in the side chain, such as a phenylstructure, thienyl structure or cyclohexyl structure (“unusual PHA”).

In addition, according to the present invention, one or more types ofpolyhydroxyalkanoate represented by the chemical formula (1) is added toa toner composition as a charge controlling agent having excellentelectrification characteristics, improved dispersibility and spentcharacteristics, to provide a toner for developing electrostatic latentimages, causing no image fogging, having excellent transfer propertiesin an image forming apparatus and high applicability to anelectrophotographic process. In addition, the charge controlling agentfor use in the present invention is characterized in that because it iscolorless or only weakly colored, any colorant can be selected accordingto the color required for the color toner, and original colors possessedby dyes and pigments are not impaired. In addition, the toner fordeveloping electrostatic images has a very high level of safety, and isbiodegradable, and therefore it can be disposed without burningtreatment, thus bringing about a significant effect in industry forpreservation of environments, such as prevention of air pollution andglobal warming.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic explanatory view of an image forming apparatusused in Examples 50 to 76 and Comparative Examples 7 to 12;

FIG. 2 is a sectional view of a principal part of a developmentapparatus for a two-component developer used in Examples 50 to 76 andComparative Examples 7 to 12;

FIG. 3 is a schematic explanatory view of a development apparatus havinga reuse mechanism of a toner used in Examples 77 to 91 and ComparativeExamples 13 to 15;

FIG. 4 is a sectional view of a principal part of a developmentapparatus for a one-component developer used in Examples 77 to 91 andComparative Examples 13 to 15;

FIG. 5 is an exploded perspective view of a principal part of a fixationapparatus used in the Example of the present invention;

FIG. 6 is an enlarged sectional view of a principal part showing a filmstate of the fixation apparatus used in the Example of the presentinvention at the time when it is not driven; and

FIG. 7 is a schematic view showing a blow-off charge level measuringapparatus for measuring the charge level of the toner.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will be described further in detail showingpreferred embodiments. As a result of intensive study for achieving theabove object, the inventors have found that the abovepolyhydroxyalkanoate has excellent characteristics as a chargecontrolling agent, and has a high level of safety for human bodies andenvironments, and that a significant effect is exhibited when a tonerfor developing electrostatic latent images (hereinafter referred to as“toner”) contains the charge controlling agent and the toner is used inan image forming apparatus having a certain development system,resulting in completion of the present invention.

That is, the present invention is a charge controlling agent containingthe above polyhydroxyalkanoate, and further a toner containing thecharge controlling agent. The present invention is further an imageforming method comprising the steps of: charging an electrostatic latentimage carrier by applying a voltage to a charging member from theoutside; forming a toner image on the electrostatic latent imagecarrier; transferring the toner image on the electrostatic latent imagecarrier to a recording medium via or not via an intermediate transfermedium; and fixing the toner image on the recording medium by heat. Thepresent invention is also an image forming apparatus comprising meanscorresponding to respective steps of the above method, namely chargingmeans, developing means, transferring means and heat-fixing means.

Polyhydroxyalkanoate for use in the present invention has a basicskeleton as a biodegradable resin. It can be used for producing variouskinds of products by melt-processing and the like as with theconventional plastics, and also has a remarkable characteristic suchthat it is decomposed by microorganism to be involved in the materialcycle in the natural world unlike synthetic polymers derived from oil.Therefore, it is an effective material in a sense that it can bedisposed without burning process and thus contributes to prevention ofair pollution and global warming as a plastic enabling preservation ofenvironments.

Polyhydroxyalkanoate suitable as a charge controlling agent for use inthe toner of the present invention will be specifically described.

Polyhydroxyalkanoate for use in the present invention is a polyesterresin containing 3-hydroxyalkanoate as a monomer unit, which has atleast one type of 3-hydroxy-ω-carboxyalkanoic acid units represented bythe chemical formula (1)

wherein n is an integer selected from the range shown in the samechemical formula; R₁ is an H atom, Na atom, K atom, or a group expressedby one of the following formulas:

and when more than one unit exists, n and R₁ may differ from unit tounit.

Furthermore, the polyhydroxyalkanoate may contain, besides the3-hydroxy-ω-carboxyalkanoic acid unit represented by the chemicalformula (1), one or both of 3-hydroxy-ω-alkanoic acid units representedby the following chemical formulas (6) and (7) respectively:

wherein m is an integer selected from the range shown in the samechemical formula; R₆ comprises a residue having either a phenylstructure or a thienyl structure; and when more than one unit exists, mand R₆ may differ from unit to unit;

wherein R₇ represents a substitute in the cyclohexyl group and is an Hatom, a CN group, an NO₂ group, a halogen atom, a CH₃ group, a C₂H₅group, a C₃H₇ group, a CF₃ group, C₂F₅ group or a C₃F₇ group; and k isan integer selected from the range shown in the same chemical formula,and when more than one unit exists, R₇ and k may differ from unit tounit.

Here, when polyhydroxyalkanoate is produced by a microorganism, thepolyhydroxyalkanoate is an isotactic polymer composed only of R form,but it is not particularly limited to the isotactic polymer and anatactic polymer can be also used as long as the object of the presentinvention can be achieved in terms of both properties and functions.Also, the PHA can be obtained by a chemical synthesis using ring openingpolymerization of a lactone compound or the like.

Examples of methods for producing polyhydroxyalkanoate for use in thepresent invention will be described below. The polyhydroxyalkanoaterepresented by the chemical formula (1) of the present invention can beproduced by oxidizing the double bonding portion of polyhydroxyalkanoatecontaining a 3-hydroxy-ω-alkanoic acid unit represented by the chemicalformula (19), a starting material.

wherein p is an integer selected from the range shown in the samechemical formula, and when more than one unit exists, P may differ fromunit to unit.

Examples of known methods of oxidizing and cleaving a carbon-carbondouble bond into carboxylic acid using an oxidizing agent are: a methodusing permanganate (J. Chem. Soc., Perkin. Trans. 1, 806 (1973)); amethod using bichromate (Org. Synth., 4, 698 (1963)); a method usingperiodate (J. Org. Chem., 46, 19(1981)); a method using a nitrate(Japanese Patent Application Laid-Open No. 59-190945); and a methodusing ozone (J. Am. Chem. Soc., 81, 4273 (1959)). Further, as topolyhydroxyalkanoates, a method is reported in Macromolecular Chemistry,4, 289-293 (2001), in which the carbon-carbon double bond at the end ofpolyhydroxyalkaniate side chain is oxidized under acid conditions usingpotassium permanganate, as an oxidizing agent, to obtain carboxylicacid. In this invention, the same method can be used.

Preferred oxidizing agents used in this invention are, not limited to,permanganates. Of permanganates, potassium permanganate is generallyused as an oxidizing agent. The amount of permanganate used should beusually 1 mol equivalent or more per mol of unit represented by thechemical formula (19) and preferably 2 to 10 mol equivalent, sinceoxidation and cleavage reaction proceeds stoichiometrically.

To make a reaction system acidic, various inorganic acids, such assulfuric acid, hydrochloric acid, acetic acid and nitric acid, andorganic acids are usually used. However, when using an acid such assulfuric acid, nitric acid or hydrochloric acid, the ester bond of thepolyhydroxyalkaniate backbone chain might be broken, causing decrease inmolecular weight. Accordingly, acetic acid is preferably used. Theamount of acid used is usually in the range of 0.2 to 2000 molequivalent per mol of unit represented by the chemical formula (19) andpreferably in the range of 0.4 to 1000 mol equivalent. The amount lessthan 0.2 mol equivalent gives the carboxyl acid in a low yield, whereasthe amount more than 2000 mol equivalent gives the acid degradationproducts as by-product. Therefore neither case are preferable.

In order to accelerate the reaction, crown ether can also be used. Inthis case, crown ether and permanganate form a complex to increase thereactivity. As the crown ether, dibenzo-18-crown-6-ether,dicyclo-18-crown-6-ether or 18-crown-6-ether is generally used. Theamount of crown ether used is usually in the range of 0.005 to 2.0 molequivalent per mol of permanganate and preferably in the range of 0.01to 1.5 mol equivalent.

As a solvent used in the oxidation reaction of this invention, anysolvents can be used as long as they are inactive in the oxidationreaction. For example, water; acetone; ethers such as tetrahydrofuranand dioxane; aromatic hydrocarbons such as benzene, toluene and xylene;aliphatic hydrocarbons such as hexane and heptane; and hydrocarbonhalides such as methyl cloride, dicloromethane and chloroform can beused. Of these solvents, hydrocarbon halides, such as methyl chloride,dichloromethane and chloroform, and acetone are preferable, taking intoconsideration the solubility of polyhydroxyalkanoates.

In the above described oxidation reaction, a polyhydroxyalkanoatecopolymer including a unit represented by the chemical formula (19), apermanganate and an acid may be introduced into a solvent at a time fromthe beginning and reacted together, or they may be separately added tothe reaction system continuously or intermittently to be reacted. Or, apermanganate alone is dissolved or suspended in a solvent, followed bycontinuous or intermittent addition of a polyhydroxyalkanoate and anacid to the reaction system, or first a polyhydroxyalkanoate alone isdissolved or suspended in a solvent, followed by continuous orintermittent addition of a permanganate and an acid to the reactionsystem. Alternatively, first a polyhydroxyalkanoate and an acid areintroduced into a solvent and then a permanganate is added to thereaction system continuously or intermittently to be reacted, or firstpermanganate and an acid are introduced into a solvent and thenpolyhydroxyalkanoate is added to the reaction system continuously orintermittently, or first a polyhydroxyalkanoate and a permanganate areintroduced into a solvent and then an acid is added to the reactionsystem continuously and intermittently to be reacted.

The reaction temperature should be usually −40 to 40° C. and preferably−10 to 30° C. The reaction time should be usually 2 to 48 hours, thoughit depends on the stoichiometric ratio of the ω-alkenoic acid unitrepresented by the chemical formula (19) to the permanganate and thereaction temperature.

When using a polyhydroxyalkanoate that includes a3-hydroxy-ω-substituted alkanoic acid unit represented by the chemicalformula (6) or a 3-hydroxy-ω-cyclohexyl alkanoic acid unit representedby the chemical formula (7), besides a 3-hydroxy-ω-alkenoic acid unitrepresented by the chemical formula (19), the reaction can be conductedunder the same conditions.

As described above, polyhydroxyalkanoate containing a unit representedby the chemical formula (1), which is an object to be obtained in thepresent invention, is produced from polyhydroxyalkanoate containing a3-hydroxy-ω-alkenoic unit having a carbon-carbon double bond at the endof the side chain, represented by the chemical formula (19), which isused as a starting material.

Polyhydroxyalkanoate containing a unit expressed by the Chemical Formula(19), which is used as a starting material in the present invention maybe produced by, but not specifically limited to, by a microbialproduction process, by a bioengineered plant crop system or by chemicalpolymerization. Preferably, the method of production by a microbialproduction process is used.

Production methods where polyhydroxyalkanoate containing a3-hydroxy-ω-alkenoic unit represented by the chemical formula (19) isused as a starting material in the present invention will be described.

The above polyhydroxyalkanoate as a starting material is produced byculturing a production microorganism in a culture medium containingω-alkenoic represented by the chemical formula (20):

wherein q is an integer selected from the range shown in the chemicalformula.

The microorgansm for use in producing polyhydroxyalkanoate containing aunit represented by the chemical formula (19) as a starting material inthe present invention may be any microorganism as long as it is amicroorganism having a PHA production capability, namely, amicroorganism capable of producing a PHA-type polyester containing a3-hydroxy-ω-alkenoic unit expressed by General Formula (19) by culturingthe microorganism in a culture medium containing ω-alkenoic acidrepresented by the chemical formula (20). One example of suitable usablemicroorganism having a PHA production capability may be a microorganismbelonging to genus Pseudomonas.

More specifically, among microorganisms belonging to Pseudomonas, morepreferable species as the microorganism for use in the production methodof the present invention may include Pseudomonas cichorii, Pseudomonasputida, Pseudomonas fluorecense, Pseudomonas oleovolans, Pseudomonasaeruginosa, Pseudomonas stutzeri and Pseudomonas jessenii.

Further, a more suitable strain includes, for example, Pseudomonascichorii YN2 (FERM BP-7375), Pseudomonas cichorii H45 (FERM BP-7374),Pseudomonas jessenii P161 (FERM BP-7376) and Pseudomonas putida P91(FERM BP-7373). These four types of strains are deposited on Nov. 20,2000 at International Patent Organism Depositary, National Institute ofBioscience and Human-Technology, Agency of Industry Science andTechnology (independent administrative corporation), Tsukuba Central 6,1-1, Higashi 1-chome, Tsukuba-shi, Ibaraki-ken 305-8566, Japan, anddescribed in Japanese Patent Application Laid-Open No. 2002-80751.

These microorganisms are capable of producing polyhydroxyalkanoatcontaining a corresponding ω-substituted-3-hydroxy-alkanoic acid as amonomer unit using as a raw material a ω-substituted-straight chainalkanoic acid substituted at the chain terminal with a six-membered ringatom group such as a substituted or unsubstituted phenyl group, asubstituted or unsubstituted phenoxy group and a substituted orunsubstituted cyclohexyl group, or a ω-substituted-straight chainalkanoic acid substituted at the chain terminal with a five-memberedring atom group such as a thienyl group.

In the production method of the present invention, any culture mediummay be used in the process of culturing a microorganism as long as it isan inorganic salt culture medium containing a phosphate and a nitrogensource such as an ammonium salt or nitrate. In the process of producingPHA in the microorganism, the productivity of PHA may be improved byadjusting the concentration of the nitrogen source.

In addition, nutrients such as an yeast extract, polypeptone and meatextract can be added to the culture medium as a substrate for promotingthe propagation of the microorganism. That is, peptides may be added asan energy source and a carbon source in the form of nutrients such as anyeast extract, polypeptone and a meat extract.

Alternatively, the culture medium may contain saccharides, for example,aldoses such as glyceroaldehyde, erythrose, arabinose, xylose, glucose,galactose, mannose and fructose, alditols such as glycerol, erythritoland xylitol, aldonic acids such as gluconic acid, uronic acids such asglucuronic acid and galacturonic acid, and disaccharides such asmaltose, sucrose and lactose as an energy source and carbon sourceconsumed for propagation of the microorganism.

Instead of the above described saccharides, organic acids or saltsthereof, more specifically organic acids involved in the TCA cycle andorganic acids derived from the TCA cycle by a biochemical reaction of afew steps, or water soluble salts thereof may be used. As the organicacid or salt thereof, hydroxycarboxylic acids and oxocarboxylic acidssuch as pyruvic acid, oxalacetic acid, citric acid, isocitric acid,ketoglutaric acid, succinic acid, fumaric acid, malic acid and lacticacid or water soluble salts thereof can be used. Alternatively, aminoacids or salts thereof, for example amino acids such as asparatic acidand glutamic acid or salts thereof can be used. When the organic acid orsalt thereof is added, it is more preferable that one or more types areselected from a group consisting of pyruvic acid, oxalacetic acid,citric acid, isocitric acid, ketoglutaric acid, succinic acid, fumaricacid, malic acid, lactic acid and salts thereof, and added to theculture medium and dissolved therein. Alternatively, when the amino acidor salt thereof is added, it is more preferable that one or more typesare selected from a group consisting of asparaginic acid, glutamic acidand salts thereof, and added to the culture medium and dissolvedtherein. At this time, as required, all or part thereof can be added inthe form of a water soluble salt to be dissolved uniformly withoutaffecting the pH of the culture medium.

It is desirable that the concentration of the above coexisting substrateadded to the culture medium as a carbon source for growth of themicroorganism and energy source for production of polyhydroxyalkanoateis usually selected so that it is in the range of from 0.1 to 5% (w/v),more preferably 0.2 to 2% (w/v) per culture medium. That is, forpeptides, yeast extracts, organic acids or salts thereof, amino acids orsalts thereof, and saccharides, which are used as the above coexistingsubstrates, one or more types thereof may be added, and, it is desirablethat the total concentration of these added substrates is with in theabove described range of total concentrations.

It is desirable that the content of the substrate for production ofdesired polyhydroxyalkanoate, namely ω-alkenoic acid expressed bygeneral formula (20) is selected so that it is in the range of from 0.01to 1% (w/v), more preferably 0.02 to 0.2% (w/v) per cultural medium.

Any temperature at which microorganism strains to be used can suitablybe propagated may be selected as a culture temperature, and anappropriate temperature is usually in the range of from about 15 to 37°C., more preferably from about 20 to 30° C.

Any culture method such as liquid culture and solid culture may be usedfor the culture as long as it allows propagation of microorganism andproduction of PHA. In addition, any type of culture method such as batchculture, fed-batch culture, semi-continuous culture and continuousculture may be used. Forms of liquid batch culture include a method ofsupplying oxygen by shaking the microorganism in a shaking flask, and amethod of supplying oxygen by aeration-agitation using a jar fermenter.

For the method of making the microorganism produce and accumulate PHA, atwo-step culture method in which the microorganism is cultured by twosteps may be adopted other than the one-step culture method in which themicroorganism is cultured in an inorganic salt culture medium containinga phosphate and a nitrogen source such as an ammonium salt or a nitratewith the substrate added therein in a predetermined concentration asdescribed above. In this two-step culture method, the microorganism isonce propagated sufficiently in the inorganic salt culture mediumcontaining a phosphate and a nitrogen source such as an ammonium salt ora nitrate with a substrate added therein in a predeterminedconcentration as a primary culture, and thereafter cells obtained by theprimary culture are transferred to a culture medium containing thesubstrate in a predetermined concentration where the amount of nitrogensource such as ammonium chloride is limited, and are further cultured asa secondary culture, thereby making the microorganism produce andaccumulate PHA. Use of this two-step culture method may improve theproductivity of desired PHA.

Generally, a produced PHA type polyester has reduced water solubilitybecause of the presence of hydrophobic atomic groups such as a4-vinylalkyl group derived from of 3-hydroxy-ω-alkenoic acid unit in theside chain, and is accumulated in cells producing PHA, and can easily beseparated from the culture medium by culturing cells and collecting thecells producing and accumulating the desired PHA type polyester. Afterthe collected cells are washed and dried, the desired PHA type polyestercan be collected.

In addition, polyhydroxyalkanoate is usually accumulated in cells ofsuch a microorganism capable of producing PHA. For the method ofcollecting desired PHA from these microorganism cells, a method that isusually used may be adopted. For example, extraction with an organicsolvent such as chloroform, dichloromethane and acetone is mostconvenient. Other than the above described solvents, dioxane,tetrahydrofuran and acetonitrile may be used. In addition, in a workingenvironment in which use of any organic solvent is not preferred, amethod in which in stead of solvent extraction, any treatment selectedfrom the following may be used: a treatment by surfactants such as SDS,a treatment by enzymes such as lysozyme, a treatment by chemicals suchas hypochlorites, ammonium and EDTA, an ultrasonic disruption method, ahomogenizer method, a pressure disruption method, a bead impulse method,a grinding method, a pounding method and a freeze-thaw method is used tophysically disrupt microorganism cells, followed by removing cellcomponents other than PHA to collect PHA.

As an example, the composition of an inorganic salt medium (M9 medium),which is used in the examples described later, is shown below.

<Composition of M9 Culture Medium>

Na₂HPO₄: 6.3

KH₂PO₄: 3.0

NH₄Cl: 1.0

NaCl: 0.5

(by g/L, pH=7.0).

Further, for ensuring satisfactory propagation of cells and associatedimprovement of productivity of PHA, essential trace elements such asessential trace metal elements should be added in an appropriate amountto an inorganic salt culture medium such as the above described M9culture medium, and it is very effective to add a solution of tracecomponents to about 0.3% (v/v), of which composition is shown below. Theaddition of such a trace component solution supplies trace metalelements for use in propagation of the microorganism.

(Composition of Trace Component Solution) nitrilotriacetic acid: 1.5;MgSO₄: 3.0; MnSO₄: 0.5; NaCl: 1.0; FeSO₄: 0.1; CaCl₂: 0.1; COCl₂: 0.1;ZnSO₄: 0.1; CuSO₄: 0.1; AlK(SO₄)₂: 0.1; H₂BO₃: 0.1; Na₂MoO₄: 0.1; NiCl₂:0.1 (g/L).

Further, in addition to ω-alkenoic acid represented by the chemicalformula (20), ω-substituted alkanoic acid represented by the followingchemical formula (21) or ω-cyclohexylakanoic acid represented by thefollowing chemical formula (22) may be added to the culture medium asthe substrate for production of desired polyhydroxyalkanoate, wherebypolyhydroxyalkanoate containing a 3-hydroxy-ω-substituted alkanoic acidunit represented by the following chemical formula (6) or a3-hydroxy-ω-cyclohexylalkanoic acid unit represented by the followingchemical formula (7) in addition to the 3-hydroxy-ω-alkenoic acid unitrepresented by the chemical formula (19) can be produced. It isdesirable that the contents of ω-alkenoic acid represented by thechemical formula (20), ω-substituted alkanoic acid compound representedby the chemical formula (21) and ω-cyclohexylakanoic acid compoundrepresented by the chemical formula (22) are in the range of 0.01% to 1%(w/v), more preferably 0.02% to 0.2% (w/v).

Here the chemical formulas (6), (7), (22) and (21) are as follows

wherein m is an integer selected from the range shown in the samechemical formula, R₂ contains a residue having either a phenyl orthienyl structure, when more than one unit exists, m and R₂ may differfrom unit to unit;

wherein R₇ represents a substitute in the cyclohexyl group and is an Hatom, a CN group, an NO₂ group, a halogen atom, a CH₃ group, a C₂H₅group, a C₃H₇ group, 5 a CF₃ group, C₂F₅ group or a C₃F₇ group; and k isan integer selected from the range shown in the same chemical formula ,and when more than one unit exists, R₇ and k may differ from unit tounit as a raw material.

wherein R₂₅ represents a substituent group in the cyclohexyl group, andis an H atom, CN group, NO₂ group, halogen atom, CH₃ group, C₂H₅ group,C₃H₇ group, CF₃ group, C₂F₅ group or C₃F₇ group, and s is an integerselected from the range shown in the chemical formula,

wherein r is an integer selected from the range shown in the chemicalformula; and R₂₄ contains a residue having either a phenyl and thienylstructure, is represented by any of the following Chemical Formulae (8),(9), (10), (11), (12), (13), (14),. (15), (16), (17) and (18), and maydiffer from unit to unit when more than one unit exits;

wherein R₈ represents a substituent on the aromatic ring and is an Hatom, a halogen atom, a CN group, an NO₂ group, a CH₃ group, a C₂H₅group, a C₃H₇ group, a CH═CH₂ group, COOR₉ (R₉ represents any one of H,Na and K atoms), a CF₃ group, a C₂F₅ group or a C₃F₇ group, and whenmore than one unit exists, R₈ may differ from unit to unit,

wherein R₁₀ represents a substituent on the aromatic ring and is an Hatom, a halogen atom, a CN group, an NO₂ group, a CH₃ group, a C₂H₅group, a C₃H₇ group, an SCH₃ group, a CF₃ group, a C₂F₅ group or a C₃F₇group, and when more than one unit exists, R₁₀ may differ from unit tounit,

wherein R₁₁ represents a substituent on the aromatic ring and is an Hatom, a halogen atom, a CN group, an NO₂ group, a CH₃ group, a C₂H₅group, a C₃H₇ group, a CF₃ group, a C₂F₅ group or a C₃F₇ group, and whenmore than one unit exists, R₁l may differ from unit to unit,

wherein R₁₂ represents a substituent on the aromatic ring and is an Hatom, a halogen atom, a CN group, an NO₂ group, a COOR₁₃, an SO₂R₁₄ (R₁₃represents any one of an H atom, an Na atom, a K atom, a CH₃ group and aC₂H₅ group and R₁₄ represents any one of an OH group, an ONa group, anOK group, a halogen atom, an OCH₃ group and OC₂H₅ group), a CH₃ group, aC₂H₅ group, a C₃H₇ group, a (CH₃)₂—CH group or a (CH₃)₃—C group, andwhen more than one unit exists, R₁₂ may differ from unit to unit,

wherein R₁₅ represents a substituent on the aromatic ring and is an Hatom, a halogen atom, a CN group, an NO₂ group, a COOR₁₆, an SO₂R₁₇ (R₁₆represents any one of an H atom, an Na atom, a K atom, a CH₃ group and aC₂H₅ group and R₁₇ represents any one of an OH group, an ONa group, anOK group, a halogen atom, an OCH₃ group and OC₂H₅ group), a CH₃ group, aC₂H₅ group, a C₃H₇ group, a (CH₃)₂—CH group or a (CH₃)₃—C group, andwhen more than one unit exists, R₁₅ may differ from unit to unit,

wherein R₁₈ represents a substituent on the aromatic ring and is an Hatom, a halogen atom, a CN group, an NO₂ group, a COOR₁₉, an SO₂R₂₀ (R₁₉represents any one of an H atom, an Na atom, a K atom, a CH₃ group and aC₂H₅ group and R₂₀ represents any one of an OH group, an ONa group, anOK group, a halogen atom, an OCH₃ group and OC₂H₅ group), a CH₃ group, aC₂H₅ group, a C₃H₇ group, a (CH₃)₂—CH group or a (CH₃)₃—C group, andwhen more than one unit exists, R₁₈ may differ from unit to unit,

wherein R₂₁ represents a substituent on the aromatic ring and is an Hatom, a halogen atom, a CN group, an NO₂ group, a COOR₂₂, an SO₂R₂₃ (R₂₂represents any one of an H atom, an Na atom, a K atom, a CH₃ group and aC₂H₅ group and R₂₃ represents any one of an OH group, an ONa group, anOK group, a halogen atom, an OCH₃ group and OC₂H₅ group), a CH₃ group, aC₂H₅ group, a C₃H₇ group, a (CH₃)₂—CH group or a (CH₃)₃—C group, andwhen more than one unit exists, R₂₁ may differ from unit to unit,

Alternatively, polyhydroxyalkanoate according to the present inventionhaving a 3-hydroxy-ω-carboxyalkanoic acid unit represented by formula(1) and other unit represented by formula (6) or (7) together in themolecule can be prepared by hydrolysis in the presence of an acid orbase or by hydrocracking or catalytic cracking of a polyhydroxyalkanoatecopolymer containing in the molecule a unit represented by formula (6)or (7) and a 3-hydroxy-ω-carboxyalkanoic acid unit represented by thechemical formula 23:

wherein n is an integer selected from the range shown in the samechemical formula, R₂₆ is any one of the residues shown in the formula,when more than one unit exists, n and R₁ may differ from unit to unit.

What is important in the structure of polyhydroxyalkanoates used in thisinvention is that it has a unit having an aliphatic carboxylic acid orits derivative as a side chain, just like the monomer units representedby the chemical formula (1). The units having an anionic or electronattractive group are preferable to further improve the negativelycharged properties of charge controlling agents; in actuality, thecharge controlling agent of this invention has superior negativelycharged properties.

Polyhydroxyalkanoate use in the present invention has good compatibilitywith the binder resin and excellent compatibility particularly withpolyester type binder resin. Since the toner containingpolyhydroxyalkanoate according to the present invention has a highspecific charge level and is excellent in stability with time, itprovides clear images stably in electrostatic recording even after beingstored for a long time period. PHA of the invention can be used for bothblack and color toners of negative chargeability because of itscolorlessness and negative-electrifiability.

In addition, by properly selecting the type and composition ratio ofmonomer units constituting polyhydroxyalkanoate according to the presentinvention, wide range compatibility control is made possible.

If a resin composition in which the charge controlling agent is put inmicro-phase separation state in a toner binder, no electric continuityis formed in the toner so that electric charge can stably be maintained.In addition, polyhydroxyalkanoate according to the present inventioncontains no heavy metals, and therefore when the toner is produced bysuspension polymerization or emulsion polymerization, polymerizationinhibition due to the presence of heavy metals, as found in the case ofa metal-containing charge controlling agent, does not occur, thus makingit possible to produce a toner stably.

<Addition of PHA to Toner>

In the present invention, the method for adding the above compound to atoner may be a method of internal addition to the toner and a method ofexternal addition to the toner. The addition amount of the internaladdition is generally 0.1 to 50% by weight, preferably 0.3 to 30% byweight, and further preferably 0.5 to 20% by weight as the weight ratioof the toner binder and the charge controlling agent. If it is lowerthan 0.1% by weight, the improvement degree of the charging property ofthe toner is insignificant and thus not preferable. Whereas, if it ishigher than 50% by weight, it is not preferably from an economical pointof view. Further, in the case of the external addition, the weight ratioof the toner binder and the charge controlling agent is preferably 0.01to 5% by weight, and it is particularly preferable that the compound ismechanochmically fixed on the surface of the toner. In addition,polyhydroxyalkanoate according to the present invention may be used incombination of a known charge controlling agent.

The number average molecular weight of polyhydroxyalkanoate according tothe present invention is usually 1000 to 1000000, preferably 1000 to300000. If it is less than 1000, the compound is completely compatiblewith the toner binder to make it difficult to form a discontinuousdomain, resulting in an insufficient charge level, and the fluidity ofthe toner is adversely affected. Further, if it is higher than 500000,dispersion in the toner becomes difficult.

The molecular weight of polyhydroxyalkanoate according to the presentinvention was measured by GPC (gel permeation chromatography). As aspecific GPC measurement method, the above polyhydroxyalkanoate ispreviously dissolved in a solvent capable of dissolving the same,measurements are made with a similar mobile phase. A differentialdiffraction detector (R1), ultraviolet detector (UV) or the like wasused as a detector, and a molecular weight distribution was determinedfrom an analytical curve of a standard polystyrene resin. The solventmay be selected from those capable of dissolving a polymer such asdimethyl formaldehyde (DMF) containing 0.1% by mass of LiBr, dimethylsulfoxide (DMSO), chloroform, tetrahydrofuran (THF), toluene, hexafluoroisopropanol (HFIP) and the like.

In addition, in the present invention, the above polyhydroxyalkanoatewith the ratio (Mw/Mn) of the weight average molecular weight (Mw) tothe number average molecular weight (Mn) measured as described abovebeing in the range of from 1 to 10 are preferably used.

Polyhydroxyalkanoate to be used in the present invention has a meltingpoint preferably in the range of from 20 to 150° C., especiallypreferably from 40 to 150° C., or has no melting point but a glasstransition temperature in the range of from 20 to 150° C., especiallypreferably from 40 to 150° C. If the foregoing melting point is lowerthan 20° C. or the glass transition temperature with no melting point islower than 20° C., the fluidity and the storage property of the tonerare often adversely affected. Whereas if the foregoing melting point ishigher than 150° C. or the glass transition temperature with no meltingpoint is higher than 150° C., the charge controlling agent becomesdifficult to be kneaded with the toner and the charge level distributionbecomes broad in many cases.

To measure the melting point Tm and the glass transition temperature Tgin this case, a high precision and internally heating input compensationtype differential scanning calorimeter, for example, DSC-7 from PerkinErmer Co., may be employed.

Regarding the toner binder and the electrostatic latent image developingtoner of the present invention, the weight ratio of the toner binder andthe charge controlling agent is generally 0.1 to 50% by weight,preferably 0.3 to 30% by weight, and more preferably 0.5 to 20% byweight. Regarding the composition ratio of the electrostatic latentimage developing toner of the present invention, generally the foregoingcharge controlling agent is in the range of from 0.1 to 50% by weight,the toner binder is in the range of from 20 to 95% by weight, and acoloring material is in the range of from 0 to 15% by weight withrespect to the weight of the toner and based on the necessity, amagnetic powder (a powder of a ferromagnetic metal such as iron, cobalt,nickel and the like and a compound such as magnetite, hematite, ferriteand the like) functioning as a coloring material may be added in anamount not more than 60% by weight. Further, various additives [alubricant (polytetrafluoroethylene, a lower molecular weight polyolefin,an aliphatic acid or its metal salt or amide, and the like) and othercharge controlling agents (metal-containing azo dye, metal salcylate,etc.)] may be contained. In addition, in order to improve the fluidityof the toner, a hydrophobic colloidal silica fine powder may also beemployed. The amounts of these additives are generally not more than 10%by weight on the bases of the toner weight.

In the toner of the present invention, it is preferable for at leastsome of the toner binder to form a continuous phase and at least some ofthe charge controlling agent to form discontinuous domain. As comparedwith the case where the charge controlling agent has completecompatibility with the toner binder without forming the discontinuousdomain, the added charge controlling agent is easily exposed to thesurface and effective even in a small amount. The dispersion particlediameter of the domain is preferably 0.01 to 4 μm and more preferably0.05 to 2 μm. If it is bigger than 4 μm, the dispersibility becomesinsufficient and the charge level distribution becomes broad and thetransparency of the toner is deteriorated. Whereas, if the dispersionparticle diameter is smaller than 0.01 μm, it becomes similar to thecase where the charge controlling agent has complete compatibility withthe binder without forming discontinuous domain, a large amount of thecharge controlling agent is required to be added. That at least some ofthe foregoing charge controlling agent forms the discontinuous domainand the dispersion particle size can be observed by observing a specimenof the toner with a transmission electron microscope. In order clearlyobserve the interface, it is also effective to carry out observation ofa toner specimen by electron microscope after the specimen is dyed withruthenium tetraoxide, osmium tetraoxide and the like.

Further, for the purpose of reducing the particle diameter of thediscontinuous domain formed by polyhydroxyalkanoate according to thepresent invention, a polymer compatible with polyhydroxyalkanoateaccording to the present invention and also with the toner binder may beadded as a compatible agent. The compatibility enhancing agent is, amongother things, a polymer comprising mutually graft- or block-polymerizedpolymer chains containing at least 50% by mol of monomers havingpractically similar structure to that of the constituent monomers ofpolyhydroxyalkanoate according to the present invention and polymerchains containing at least 50% by mol of monomers having practicallysimilar structure to that of the toner binder. The amount of thecompatible agent to be used is generally not more than 30% by weight andpreferably 1 to 10% by weight, with respect to polyhydroxyalkanoateaccording to the present invention.

<Other Constituent Materials>

Other constituent materials constituting the electrostatic latent imagedeveloping toner of the present invention will be described below.(Binder Resin) First, as a binder resin, any resin may be used withoutany particular restrictions if it is generally used for production of atoner. Also, the charge controlling agent of the present invention maypreviously be mixed with the binder resin to be used as a toner bindercomposition of the present invention having charge controllingcapability before production of the toner. For example, as the binderresin, styrene-based polymers, polyester-based polymers, epoxy-basedpolymers, polyolefin-based polymers, and polyurethane-based polymers,and the like can be exemplified and they are used alone or while beingmixed with one another.

The styrene-based polymers may be styrene-(meth)acrylic acid estercopolymers and copolymers of these copolymers with other monomerscopolymerizable with them; copolymers of styrene with diene typemonomers (butadiene, isoprene and the like) and copolymers of thesecopolymers with other monomers copolymerizable with them; and the like.The polyester-based polymers may be condensation polymerization productsof aromatic dicarboxylic acid and aromatic diol alkylene oxide additionproducts and the like. The epoxy-based polymers may be reaction productsof aromatic diols and epichlorohydrin and their modified products. Thepolyolefin-based polymers may be polyethylene, polypropylene, andcopolymer chains of these polymers with monomers polymerizable withthem. The polyurethane-based polymers may be addition polymerizationproducts of aromatic diisocyanates and aromatic diol alkylene oxideaddition products and the like.

Practical examples of the binder resin to be used in the presentinvention are polymers of the following polymerizable monomers or theirmixtures or copolymerization products produced from two or more kinds ofthe following polymerizable monomers. Such polymers are moreparticularly, for example, styrene-based polymers such asstyrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, andthe like; polyester-based polymers; epoxy-based polymers;polyolefin-based polymers; and polyurethane-based polymers and they arepreferably used.

Practical examples of the polymerizable monomers are styrene and itsderivatives such as styrene, o-methylstyrene, p-methylstyrene,p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene,p-ethylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene,p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene,p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, and the like;ethylenic unsaturated monoolefins such as ethylene, propylene, butylene,isobutylene and the like; unsaturated polyenes such as butadiene and thelike; vinyl halides such as vinyl chloride, vinylidene chloride, vinylbromide, vinyl fluoride and the like; vinyl esters such as vinylacetate, vinyl propionate, vinyl benzoate and the like; α-methylenealiphatic monocarboxylic acid esters such as methyl methacrylate, ethylmethacrylate, propyl methacrylate, n-butyl methacrylate, isobutylmethacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexylmethacrylate, stearyl methacrylate, phenyl methacrylate,dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and thelike; acrylic acid esters such as methyl acrylate, ethyl acrylate,n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate,dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethylacrylate, phenyl acrylate, and the like; vinyl ethers such as vinylmethyl ether, vinyl ethyl ether, vinyl isobutyl ether, and the like;vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, methylisopropenyl ketone, and the like; N-vinyl compounds such asN-vinylpyrrole, N-vinylcarbazole, N-vinylindole, N-vinylpyrrolidone andthe like; vinyl naphthalenes; acrylic acid or methacrylic acidderivatives such as acrylonitrile, methacrylonitrile, acrylamide and thelike; the above-described α, β-unsaturated acid esters; bibasic aciddiesters; dicarboxylic acids such as maleic acid, methyl maleate, butylmaleate, dimethyl maleate, phthalic acid, succinic acid, terephthalicacid, and the like; polyols compounds such as ethylene glycol,diethylene glycol, triethylene glycol, 1,2-propylene glycol,1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, bisphenol A,hydrogenated bisphenol A, polyoxyethylene-modified bisphenol A and thelike; isocyanates such as p-phenylene diisocyanate, p-xylylenediisocyanate, 1,4-tetramethylene diisocyanate, and the like; amines suchas ethylamine, butylamine, ethylenediamine, 1,4-diaminobenzene,1,4-diaminobutane, monoethanolamine, and the like; epoxy compounds suchas diglycidyl ether, ethylene glycol diglycidyl ether, bisphenol Aglycidyl ether, hydroquinone glycidyl ether, and the like.

(Cross-Linking Agent)

In the case of producing the binder resin to be used in the presentinvention, based on the necessity, the following cross-linking agent maybe used. Examples of a bifunctional cross-linking agent aredivinylbenzene, bis(4-acryloxypolyethoxyphenyl)propane, ethylene glycoldiacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate,1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycoldiacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate,tetraethylene glycol diacrylate, respective diacrylates of polyethyleneglycol #200, #400, #600, dipropylene glycol diacrylate, polypropyleneglycol diacrylate, polyester type diacrylate (MANDA Nippon Kayaku), andthose obtained by replacing these exemplified acrylates withmethacrylates.

Examples of bi- or higher polyfunctional cross-linking agent arepentaerythritol triacrylate, trimethylolethane triacrylate,trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate,oligoester acrylates or methacrylates, 2,2-bis(4-methacryloxy,polyethoxyphenyl)propane, diallyl phthalate, triallyl cyanurate,triallyl azocyanurate, triallyl isocyanurate, triallyl trimellitatediaryl chlorendate, and the like.

(Polymerization Initiator)

In the case of producing the binder resin to be used in the presentinvention, the following polymerization initiators may be used based onthe necessity: for example, tert-butyl peroxy-2-ethylhexanoate, cumineperpivalate, tert-butyl peroxylaurate, benzoyl peroxide, lauroylperoxide, octanoyl peroxide, di-tert-butyl peroxide, tert-butylcumylperoxide, dicumyl peroxide, 2,2′-azobis isobutyronitrile,2,2′-azobis(2-methylbutyronitrile),2,2′-azobis(2,4-dimethylvaleronitrile),2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile),1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane,1,1-bis(tert-butylperoxy)cyclohexane,1,4-bis(tert-butylperoxycarbonyl)cyclohexane,2,2-bis(tert-butylperoxy)octane, n-butyl4,4-bis(tert-butylperoxy)valirate, 2,2-bis(tert-butylperoxy)butane,1,3-bis(tert-butylperoxyisopropyl)benzene,2,5-dimethyl-2,5-di(tert-butylperoxy)hexane,2,5-dimethyl-2,5-di(tert-butylperoxy)hexane,2,5-dimethyl-2,5-di(benzoylperoxy)hexane, di-tert-butyldiperoxyisophthalate, 2,2-bis(4,4-di-tert-butylperoxycyclohexyl)propane,di-tert-butylperoxy-α-methylsuccinate, di-tert-butylperoxydimethylglutarate, di-tert-butyl peroxyhexahydroterephthalate,di-tert-butyl peroxyazelate,2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, diethylene glycolbis(tert-butylperoxycarbonate), di-tert-butyl peroxytrimethyladipate,tris(tert-butylperoxy)triazine, vinyltris(tert-butylperoxy)silane andthe like. Each of these compounds may be used alone or in combination.The use amount of them is generally in 0.05 parts by mass or more(preferably 0.1 to 15 parts by mass) to 100 parts by mass of monomers.

(Other Biodegradable Plastics)

In addition, in the present invention, commercially availablebiodegradable plastics are preferably used. Examples of thebiodegradable plastics are “Ecostar”, “Ecostar plus” (produced byHagiwara Industries, Inc.), “Biopole” (produced by Monsanto Company),“Ajicoat” (Ajinomoto Co., Ltd.), “Placcel”, “Polycaprolactone” (producedby Daicel Chem., Ind., Ltd.), “SHOWLEX”, “Bionolle” (produced by ShowaDenko K.K.), “Lacty” (produced by Shimadzu Corporation), “Lacea”(produced by Mitsui Chemicals, Inc.) and the like.

It is preferable for the combinations of the binder resin and the chargecontrolling agent of the present invention that the structure of thepolymers of the binder resin and the polymer structure of the polymerchain of the charge controlling agent are similar to each other as muchas possible. If the structure of the polymers of the binder resin andthe polymer structure of the polymer chain of the charge controllingagent are considerably dissimilar to each other, the charge controllingagent tends to be dispersed insufficiently in the binder resin.

The weight ratio of the charge controlling agent of the presentinvention to be internally added to the binder resin is generally 0.1 to50% by weight, preferably 0.3 to 30% by weight, and more preferably 0.5to 20% by weight. If the weight ratio of the charge controlling agent tobe internally added is lower than 0.1% by weight, the charge levelbecomes low and if the weight ratio is higher than 50% by weight, thecharge stability of the toner is deteriorated.

<Coloring Agent>

Any coloring agent generally used for production of a toner may be usedas the coloring agent composing the electrostatic latent imagedeveloping toner of the present invention without particularrestrictions. For example, carbon black, titanium white, and any otherpigment and/or dye may be used.

For example, in the case the electrostatic latent image developing tonerof the present invention is used for a magnetic color toner, examples ofthe coloring agent to be employed are C.I. Direct Red 1, C.I. Direct Red4, C.I. Acid Red 1, C.I. Basic Red 1, C.I. Mordant Red 30, C.I. DirectBlue 1, C.I. Direct Blue 2, C.I. Acid Blue 9, C.I. Acid Blue 15, C.I.Basic Blue 3, C.I. Basic Blue 5, C.I. Mordant Blue 7, C.I. Direct Green6, C.I. Basic Green 4, C.I. Basic Green 6 and the like. Examples of thepigment are Chrome Yellow, Cadmium Yellow, Mineral Fast Yellow, NavalYellow, Naphthol Yellow S, Hansa Yellow G, Permanent Yellow NCG,Tartrazine Yellow Lake, Chrome Orange, Molybenum Orange, PermanentOrange GTR, Pyrazolone Orange, Benzidine Orange G, Cadmium Red,Permanent Red 4R, Watching Red calcium salt, Eosine Lake, BrilliantCarmine 3B, Manganese Violet, Fast Violet B, Methyl Violet Lake,Prussian Blue, Cobalt Blue, Alkali Blue Lake, Victoria Blue Lake,Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue BC, Chrome Green,chromium oxide, Pigment Green B, Malachite Green Lake, Final YellowGreen G and the like.

In the case the electrostatic latent image developing toner of thepresent invention is used for a two-component type full color toner, thefollowing coloring agents can be used. For example, coloring pigmentsfor magenta toners are C.I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39,40, 41, 48, 49, 50, 51, 52, 53, 54, 55, 57, 58, 60, 63, 64, 68, 81, 83,87, 88, 89, 90, 112, 114, 122, 123, 163, 202, 206, 207, 209, C.I.Pigment Violet 19, C.I. Vat Red 1, 2, 10, 13, 15, 23, 29, 35 and thelike.

In the present invention, the above-exemplified pigments may be usedalone, but it is more preferable that they are used in combination withdyes for improving the clearness from the aspect of the full color imagequality. In such a case, the examples of usable magenta dyes areoil-soluble dyes such as C.I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30,49, 81, 82, 83, 84, 100, 109, 121, C.I. Disperse Red 9, C.I. SolventViolet 8, 13, 14, 21, 27, C.I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30,49, 81, and C.I. Disperse Violet 1 and the like; and basic dyes such asC.I. Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32,34, 35, 36, 37, 38, 39, 40, C.I. Basic Violet 1, 3, 7, 10, 14, 15, 21,25, 26, 27, 28 and the like.

As other coloring pigments, examples of cyan coloring pigments are C.I.Pigment Blue 2, 3, 15, 16, 17, C.I. Vat Blue 6, C.I. Acid Blue 45,copper-phthalocyanine pigments having a phthalocyanine skeletoncontaining substituents of phthalimidomethyl groups in number of 1 to 5,and the like.

Examples of yellow coloring pigments are C.I. Pigment Yellow 1, 2, 3, 4,5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 65, 73, 83, C.I. Vat Yellow1, 3, 20 and the like.

The above-described dyes and pigments may be used solely or may be usedwhile being optionally mixed with one another to obtain desired hue ofthe toner. When considering the environmental conservation and thesafety to the human body, various food colors can be suitably used. Thecontent of the coloring agents in the toner may widely altered dependingon the desired coloration effects. Generally, in order to obtain thebest toner properties, that is, in consideration of the printingcoloration capability, the toner shape stability, and the tonerscattering, these coloring agents are used at a ratio in the range offrom 0.1 to 60 parts by mass, preferably 0.5 to 20 parts by mass withrespect to 100 parts by mass of the binder resin.

<Other Components of Toner>

In the toner of the present invention may contain the followingcompounds other than the foregoing binder resin and the coloring agentcomponents, to an extent (within a ratio less than the content of thebinder resin) in which no undesired effect is caused in the presentinvention. Examples of such compounds include silicone resin; polyester;polyurethane; polyamide; epoxy resin; poly(vinyl butyral); rosin;modified rosin; terpene resin; phenolic resin; aliphatic or alicyclichydrocarbon resin such as lower molecular weight polyethylene and lowermolecular weight polypropylene; aromatic type petroleum resin; andchlorinated paraffin and paraffin waxes. Among them, preferable waxes tobe used are practically lower molecular weight polypropylene and itsbyproducts, lower molecular weight polyester, and ester type wax andaliphatic derivatives. Among these waxes, waxes fractionated based onthe molecular weight of the waxes by various methods are also preferablyused in the present invention. Further, after fractionation, the waxesmay be modified to control the acid values, block-copolymerized, orgraft-modified.

Specially, in the toner of the present invention, in the case such waxcomponents as described above are added and these wax components arefound practically dispersed in the binder resin in spherical and/orspindly island state when the section of the toner was observed by atransmission electron microscope, the toner has excellent properties.

<Method of Producing Toners>

Any conventionally known method may be employed for a practical methodfor producing an toner of the present invention having the constitutionas described above. The toner of the present invention can be produced,for example, by a so-called pulverization method for obtaining a tonerthrough the following steps. Specifically, resin materials such asbinder resin, and a charge controlling agent to be added as necessary, awax, are sufficiently mixed by a mixer such as a Henshel mixer, a ballmill and the like and then melted and kneaded using a thermally kneadingapparatus such as heating rolls, a kneader, an extruder and the like tomake the resin material compatible with one another, and as coloringagents, pigments, dyes, or magnetic materials and also additives such asmetal compounds to be added as necessary are dispersed or dissolved inthe resulting mixture, and after solidification of the mixture bycooling, the obtained solidified product is pulverized by a pulverizingapparatus such as a jet mill, a ball mill and the like and thenclassified to obtain an toner of the present invention with a desiredparticle size. In the above-described classification step, from anaspect of productivity, a multi-step classification apparatus ispreferably used.

In addition, the toner of the present invention with a desired particlesize can be obtained by mixing and stirring the binder resin and thecharge controlling agent in a solvent (e.g., aromatic hydrocarbons suchas toluene, xylene and the like; halogen compounds such as chloroform,ethylene dichloride, and the like; ketones such as acetone, methyl ethylketone, and the like; amides such as dimethylformamide and the like),and then adding the resulting mixture to water to re-precipitate thesolid, then filtering and drying the solid, and further pulverizing itby a pulverizing apparatus such as a jet mill, a ball mill, and thelike, and finally classifying the pulverized matter. In theabove-described classification step, from an aspect of productivity, amulti-step classification apparatus is preferably used.

In addition, the toner of the present invention can be produced by aso-called polymerization method as follows. That is, in this case, apolymerizable monomer of a binder resin, a charge controlling agent andas coloring agents, pigments, dyes, or magnetic materials and also basedon the necessity, additives such as a cross-linking agent, apolymerization initiator, waxes, other binder resins, and others aremixed and dispersed and in the presence of a surfactant or the like, themixture is subjected to suspension polymerization to obtain apolymerized and colored resin particles, and after the obtainedparticles are separated by solid-liquid separation, the particles aredried and classified if necessary to obtain a toner of the presentinvention with a desired particle size. Furthermore, colored fineparticles containing no charge controlling agent is produced by theabove-described manner and then either solely or together with anexternally added agent such as colloidal silica, the abovepolyhydroxyalkanoate may be attached and fixed to the surface of theparticle by a mechanochemical method or the like.

<Externally Added Silica Agent>

In the present invention, a silica fine powder is preferably addedexternally to the toner produced in a manner as described above forimproving the charge stability, development characteristic, fluidity anddurability. The silica fine powder to be employed in this case canprovide desirable effects if it has a specific surface area of 20 m²/gor higher (especially 30 to 400 m²/g) measured based on the nitrogenadsorption by the BET method. The content of the silica fine powder tobe added is preferably 0.01 to 8 parts by weight, more preferably 0.1 to5 parts by weight, with respect to 100 parts by weight of the tonerparticles. In this case, based on the necessity, the silica fine powderto be used in the case is preferably treated, for the purpose ofcontrolling the hydrophobicity and charge properties, with siliconevarnish, variously modified silicone varnish, silicone oil, variouslymodified silicone oil, a silane coupling agent, a silane coupling agenthaving a functional group, and other organosilicon compounds. Thesetreatment agent may be used by mixing.

<Inorganic Powder>

Further, in order to improve the development capability and thedurability, the following inorganic powder is preferably added. Examplesof the powder are oxides of metals such as magnesium, zinc, aluminum,cerium, cobalt, iron, zirconium, chromium, manganese, strontium, tin,antimony and the like; compounded metal oxides such as calcium titanate,magnesium titanate, and strontium titanate; metal salts such as calciumcarbonate, magnesium carbonate, and aluminum carbonates; clay mineralssuch as kaolin; phosphate compounds such as apatite; silicon compoundssuch as silicon carbide, and silicon nitride; and carbon powder such ascarbon black and graphite. Among them, fine powders of zinc oxide,aluminum oxide, cobalt oxide, manganese dioxide, strontium titanate, andmagnesium titanate are preferably used.

<Lubricant>

Further, the following lubricant powder may be added to the toner. Forexample, fluoro resin such as Teflon, poly(vinylidene fluoride) and thelike; fluoride compounds such as carbon fluoride; aliphatic acid metalsalts such as zinc stearate; aliphatic acid derivatives such asaliphatic acid, aliphatic acid esters and the like; and molybdenumsulfide.

The contents, in a toner, of the binder resins, colorants, chargecontrolling agents used in the form of a mixture with the binder resinof this invention and those of other additives added as the need arisesare very small; however, it is preferable to use the binder resins,colorants, charge controlling agents and other additives each havingbiodegradability, if possible, taking into consideration their effectson the environment after use.

<Carrier>

The toner of the present invention having the above-describedconstitution is usable for a variety of conventionally known toners;solely as a non-magnetic one-component developer, as a non-magnetictoner together with a magnetic carrier for composing a magnetictwo-component developer, as a magnetic toner to be used solely for amagnetic mono-component toner. In this case, as the carrier to be usedfor the two-component development, any conventionally known carrier maybe used. More particularly, particles of surface-oxidized ornon-oxidized metals such as iron, nickel, cobalt, manganese, chromiumand rare earth metals, their alloys and oxides and having an averageparticle size of 20 to 300 μm may be used as the carrier particles.Further, the carrier to be used in the present invention are preferablythe above-described carrier particle whose surface bears or is coatedwith a substance such as styrene-based resin, acrylic resin, siliconeresin, fluoro resin, polyester resin and the like.

<Magnetic Toner>

The toner of the present invention may be a magnetic toner by adding amagnetic material to the toner particles. In this case, the magneticmaterial may take a role also as a coloring agent. The magnetic materialto be used in this case may be iron oxides such as magnetite, hematite,and ferrite; metals such as iron, cobalt, and nickel; alloys of thesemetals with metals such as aluminum, cobalt, copper, lead, magnesium,tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese,selenium, titanium, tungsten, and vanadium; and their mixtures. Themagnetic material to be used in the present invention has an averageparticle size preferably 2 μm or smaller, more preferably 0.1 to 0.5 μm.The amount to be added to the toner is preferably 20 to 200 parts byweight to 100 parts by weight of the binder resin and especiallypreferably 40 to 150 parts by weight to 100 parts by weight of thebinder resin.

In addition, in order to give high image quality, it is required toprecisely develop very small latent image dots and for this purpose, forexample, it is preferable that the weight average particle size of thetoner of the present invention is controlled so that it is in the rangeof from 4 to 9 μm. That is, if the toner particle has a weight averageparticle size smaller than 4 μm, the transfer efficiency is decreasedand a large amount of the transfer residual toner tends to remain on aphotosensitive member to result in an undesirable cause of uneven andirregular image formation due to fogging and transfer failures. Whereas,if the toner particle has a weight average particle size larger than 9μm, scattering around letters and line images tends to occur.

In the present invention, the average particle size and the particlesize distribution of the toner are measured by using Coulter CounterTA-II model or Coulter Multisizer (manufactured by Coulter Co.) or thelike to which an interface (manufactured by Nikka Machine Co.) foroutputting the distribution by number, the distribution by volume and aPC9801 personal computer (manufactured by NEC) are connected. As anelectrolytic solution to be used at that time, an aqueous 1% NaClsolution is prepared using first-grade sodium chloride. As theelectrolytic solution, for example, a commercialized ISOTON R-II(produced by Coulter Scientific Japan Co.) may also be usable. Apractical measurement method involves steps of adding 0.1 to 5 mL of asurfactant (preferably an alkylbenzenesulfonic acid salt is used) as adispersant to 100 to 150 mL of the above-described aqueous solution,further adding 2 to 20 mg of a sample to the resulting solution toobtain a specimen to be measured. At the time of measurement, theelectrolytic solution in which the specimen to be measured is suspendedis treated for dispersion for 1 to 3 minutes by an ultrasonic dispersingapparatus and then the volume and the number of the toner particles of 2μm or larger are measured by the foregoing Coulter Counter TA-II modelusing 100 μm aperture and the distribution by volume and thedistribution by number are calculated. Then, the weight average particlesize (D4) on the basis of the volume calculated from the distribution byvolume according to the present invention and the length averageparticle size (D1) on the basis of the number calculated from thedistribution by number are calculated.

<Charge Level>

In addition, the charge level of the toner of the present invention ispreferably in the range of from −10 to <80 μC/g, more preferably from−15 to −70 μC/g per unit weight (two-component method) in improving thetransfer efficiency in a transfer method using a transfer member with avoltage applied thereto.

The method of measuring a charge level (a two-component tribo) by thetwo-component method employed in the present invention will be describedas follows. A charge level measuring apparatus illustrated in FIG. 7 isused for the measurement. At first, under a specified environment, EFV200/300 (produced by Powder Tec Co.) is used as a carrier and a bottlemade of a polyethylene with a capacity of 50 to 100 mL is charged with amixture of 9.5 g of the carrier and 0.5 g of a toner to be measured, setin a shaking apparatus so controlled as to keep the amplitude constant,and shaken for a prescribed period in the shaking conditions of anamplitude of 100 mm and a shaking speed of 100 rpm. Then, 1.0 to 1.2 gof the above mixture is placed in a measurement container 42 made ofmetal having a 500-mesh screen 43, and the measurement container 42 iscovered with a metal lid 44 in the bottom of the charge level measuringapparatus shown in FIG. 7. The total weight of the measurement container42 at that time is measured and determined as W1 (g). Next, the gas inthe container is aspirated through a suction port 47 by an unillustratedaspirator (at least the portion contacting the measurement container 42is made of an insulator) and an air ventilation adjustment valve 46 iscontrolled to control the pressure of the vacuum meter 45 to be 2,450 Pa(250 mmAq). Under such a state, aspiration is carried out for 1 minuteto suck and remove the toner. The potential of a potentiometer 49 atthat time is denoted as V (volt). The reference numeral 48 denotes acapacitor and the capacity is denoted as C (μF). The weight of theentire measurement container after the aspiration is weighed and denotedas W2 (g). The friction charge level (μC/g) of the toner can becalculated according to the following equation from these measurementvalues.

Friction charge level (μC/g)=C×V/(W1−W2)

<Method for Measuring Molecular Weight of Binder Resin and MolecularWeight Distribution>

The binder resin for use in the constituent material of the toner of thepresent invention preferably has a peak within the range of from 3,000to 15,000 in a low molecular weight region of the molecular weightdistribution measured by GPC, especially, in the case of production bythe pulverization method. That is, if the GPC peak exceeds 15,000 in thelow molecular weight region, it sometimes becomes difficult to obtain atoner with a sufficiently improved transfer efficiency. Whereas ifbinder resin having a GPC peak of less than 3,000 is used, melting takesplace easily at the time of surface treatment and therefore it isundesirable.

In the present invention, the molecular weight of the binder resin ismeasured by GPC (gel permeation chromatography). A practical GPCmeasurement method is carried out as follows: a toner previouslyextracted with THF (tetrahydrofuran) solvent for 20 hours using aSoxhlet extractor is used as a sample for measurement. Using columnsA-801, 802, 803, 804, 805, 806, and 807 manufactured by Showa Denko K.K.and the calibration curve of standardized polystyrene resins, themolecular weight distribution is measured. Further, in the presentinvention, it is preferable that the binder resin with the ratio (Mw/Mn)of the weight average molecular weight (Mw) to the number averagemolecular weight (Mn) measured as described above being in the range offrom 2 to 100 is used.

<Glass Transition Temperature of Toner>

Further, the toner of the present invention is preferably adjusted byusing a proper material so as to have a glass transition temperature Tgin the range of from 40 to 75° C., more preferably 52 to 70° C., from aviewpoint of fixation and storage stability. In this case, themeasurement of the glass transition temperature Tg may be carried outusing a high precision and internally heating input compensation typedifferential scanning calorimeter, for example, DSC-7 manufactured byPerkin Elmer Co., may be employed. The measurement method is carried outaccording to ASTM D3418-82. In the present invention, when the glasstransition temperature Tg is measured, it is preferable that ameasurement sample is once heated to cancel the entire hysteresis andthen cooled rapidly and again heated at a heating rate of 10° C./min toemploy the DSC curve measured during the heating from 0 to 200° C.

<Image Formation Method>

The toner of the present invention having the configuration describedabove is particularly preferably applied to an image formation methodand an apparatus therefor, the method comprising at least an chargingstep of applying a voltage to a charging member from the outside tocharge an electrostatic latent image-holding member, a step of formingan electrostatic latent image on the charged electrostatic latentimage-holding member, a development step of developing the electrostaticlatent image with the toner to form a toner image on the electrostaticlatent image-holding member, a transfer step of transferring the tonerimage on the electrostatic latent image-holding member to a recordingmaterial, and a heat-fixation step of heat-fixing the toner image on therecording material. Alternatively, an image formation method and anapparatus therefor can be used where the transfer step consists of afirst transfer step of transferring the toner image on the electrostaticlatent image-holding member to an intermediate transfer member and asecond transfer step of transferring the toner image on the intermediatetransfer member to the recording material.

The culture of microorganisms, the recovery of the PHA from themicroorganisms, the resin compositions and the moldings, and inaddition, the toner binder resins, the charge controlling agents, etc.of this invention are all not limited to the above described methods.

EXAMPLES

The present invention will be further described in the followingExamples and Comparative Examples. The Examples are not intended tolimit the scope of the present invention. The number of parts in each ofthe following compositions represents part by mass. Moreover, “%” hereinrepresents mass standard, unless otherwise specified.

First, a method for preparing polyhydroxyalkanoate of the presentinvention comprising a microbiological production step followed by achemical processing step is shown below (Examples 1 to 5).

(Example 1)

<Pre-Preparation 1: Biosynthesis of ω-Alkene PHA (1)>

20 shaking flasks (volume: 500 mL) were prepared. Thereafter, 0.5 wt %polypeptone (Wako Pure Chemical Industries, Ltd.), 6 mmol/L5-phenoxyvaleric acid, and 3.75 mmol/L 10-undecenoic acid were dissolvedin 200 mL of the above M9 medium, and the resultant solution was placedin each of the above 500 mL shaking flasks and was then sterilized by anautoclave and cooled to room temperature. Pseudomonas cichorii YN2 wasshake-cultured for 8 hours in an M9 medium supplemented with 0.5%polypeptone, and 2 mL of the preculture was added to each of the aboveprepared media, and cultured at 30° C. for 64 hours. After completion ofthe culture, they were combined, and cells were recovered bycentrifugation. The obtained cells were washed with methanol and thendried. After weighing the dried cells, chloroform was added thereto, andthe mixture was stirred at 35° C. for 72 hours to extract a polymer. Thechloroform containing the extracted polymer was filtrated through a 0.45μm membrane filter, and the filtrate was concentrated using anevaporator. The condensate was then reprecipitated with cold methanol,to recover a polymer. Thereafter, the obtained polymer was dried underreduced pressure to obtain a polymer of interest.

The obtained polymer and lyophilized cells (weight of dried cells) wereweighed. In the present example, 1,528 mg of PHA (dry weight) wasobtained.

The average molecular weight of the obtained PHA was evaluated by gelpermeation chromatography (GPC: Tosoh HLC-8220, column: Tosoh TSK-GELSuper HM-H, solvent: chloroform, polystyrene conversion). As a result,number average molecular weight Mn=104,000, and weight average molecularweight Mw=231,000.

Moreover, in order to identify the structure of the obtained PHA, an NMRanalysis was carried out under the following conditions:

Measuring apparatus FT-NMR: Bruker DPX 400

Resonance frequency: ¹H=400 MHz

Measuring conditions:

Type of nuclear species: ¹H

Used solvent: TMS/CDCl₃

Temperature: room temperature

As a result, it was confirmed that the obtained PHA was apolyhydroxyalkanoate copolymer comprised of, as monomer units,3-hydroxy-5-phenoxyvaleric acid, 3-hydroxy-10-undecenoic acid,3-hydroxy-8-nonenoic acid, and 3-hydroxy-6-heptenoic acid represented bythe following chemical formulas (24), (25), (26) and (27) respectively.

From the ¹H-NMR spectrum, it was confirmed that the proportion of theseunits was 69 mol % of 3-hydroxy-5-phenoxyvaleric acid, 23 mol % of thetotal three units, 3-hydroxy-10-undecenoic acid, 3-hydroxy-8-nonenoicacid, and 3-hydroxy-6-heptenoic acid, and 8 mol % of others (straightchain 3-hydroxyalkanoic acid having 4 to 12 carbon atoms, and3-hydroxyalka-5-enoic acid having 10 or 12 carbon atoms).

From this result, it was confirmed that the obtained PHA contains theunit of 3-hydroxy-10-undecenoic acid as represented by chemical formula(19).

<Synthesis of Aliphatic Carboxy PHA by Oxidative Reaction (1)>

303 mg of polyhydroxyalkanoate obtained by pre-preparation 1 was addedinto a 200 mL round bottomed flask, and 20 mL of dichloromethane wasfurther added thereto, so that the above compound was dissolved. Theresultant product was left under ice bath cooling, and 3 mL of aceticacid and 300 mg of 18-crown-6-ether were then added thereto, followed bystirring. Thereafter, 241 mg of potassium permanganate was slowly addedthereto under ice bath cooling, and the mixture was stirred at roomtemperature for 20 hours. After completion of the reaction, water (50mL) and sodium hydrogen sulfite were added to the reaction product.Thereafter, 1.0 mol/L (1.0 N) hydrochloric acid was added thereto, sothat the mixed solution was adjusted to pH 1. Dichloromethane containedin the mixed solution was removed on an evaporator, and thereafter, thepolymer in the solution was recovered. The recovered polymer was washedwith 100 mL of methanol and then with 100 mL of pure water three times,and thereafter the polymer was recovered. The recovered polymer wasdried under reduced pressure, so as to obtain 247 mg of PHA of interest.

The average molecular weight of the obtained PHA was evaluated by gelpermeation chromatography (GPC: Tosoh HLC-8220, column: Tosoh TSK-GELSuper HM-H, solvent: chloroform, polystyrene conversion). As a result,number average molecular weight Mn=29,400, and weight average molecularweight Mw=102,800.

In order to specify the structure of the obtained PHA, an NMR analysiswas carried out under the above-described conditions.

As a result, it was confirmed that the obtained PHA was apolyhydroxyalkanoate copolymer comprised of monomer units,3-hydroxy-5-phenoxyvaleric acid, 3-hydroxy-9-carboxynonanoic acid,3-hydroxy-7-carboxyheptanoic acid, and 3-hydroxy-5-carboxyvaleric 5 acidrepresented by the following chemical formulas (24), (28), (29) and (30)respectively.

Moreover, in order to calculate the ratio of the units of the obtainedPHA, a carboxyl group located at the end of the side chain of PHA wasmethyl-esterified using trimethylsilyldiazomethane. 50 mg of PHA ofinterest was added into a 100 mL round bottomed flask, and 3.5 mL ofchloroform and 0.7 mL of methanol were then added thereto to dissolvethe PHA. 2 mL of 0.63 mol/L trimethylsilyldiazomethane-hexane solution(Tokyo Kasei) was added thereto, followed by stirring at roomtemperature for 30 minutes. After completion of the reaction, thesolvent was removed on an evaporator, and thereafter, a polymercontained in the solution was recovered. The recovered polymer waswashed with 50 mL of methanol, and dried under reduced pressure toobtain 49 mg of PHA.

An NMR analysis was carried out by the same method as described above.As a result, it was confirmed that the ratio of the units was 83 mol %of 3-hydroxy-5-phenoxyvaleric acid, 8 mol % of the total three units,3-hydroxy-9-carboxynonanoic acid, 3-hydroxy-7-heptanoic acid, and3-hydroxy-5-valeric acid, and 9 molt of others (straight chain3-hydroxyalkanoic acid having 4 to 12 carbon atoms, and3-hydroxyalka-5-enoic acid having 10 or 12 carbon atoms).

The above method was scaled up, so as to obtain 50 g of PHA, which wasdenoted as PHA (1).

Example 2

<Pre-Preparation 2: Biosynthesis of ω-alkene PHA (2)>

20 shaking flasks (volume: 500 mL) were prepared. Thereafter, 0.5 wt %polypeptone (Wako Pure Chemical Industries, Ltd.), 6 mmol/L4-cyclohexylbutyric acid, and 3 mmol/L 10-undecenoic acid were dissolvedin 200 mL of the above M9 medium, and the resultant solution was placedin each of the above 500 mL shaking flasks and was then sterilized by anautoclave and cooled to room temperature. Pseudomonas cichorii YN2 wasshake-cultured for 8 hours in an M9 medium supplemented with 0.5%polypeptone, and 2 mL of the preculture was added to each of the aboveprepared media, and cultured at 30° C. for 69 hours. After completion ofthe culture, they were combined, and cells were recovered bycentrifugation. The obtained cells were washed with methanol and thendried. After weighing the dried cells, chloroform was added thereto, andthe mixture was stirred at 35° C. for 72 hours to extract a polymer. Thechloroform containing the extracted polymer was filtrated through a 0.45μm membrane filter, and the filtrate was concentrated using anevaporator. The condensate was then reprecipitated with cold methanol,to recover a polymer. Thereafter, the obtained polymer was dried underreduced pressure to obtain a polymer of interest.

The obtained polymer and lyophilized cells (weight of dried cells) wereweighed. In the present example, 1,433 mg of PHA (dry weight) wasobtained.

The average molecular weight of the obtained PHA was evaluated under thesame GPC conditions as in Example 1. As a result, number averagemolecular weight Mn=143,000, and weight average molecular weightMw=458,000. Moreover, in order to specify the structure of the obtainedPHA, an NMR analysis was carried out under the same conditions as inExample 1.

As a result, it was confirmed that the obtained PHA was apolyhydroxyalkanoate copolymer comprised of monomer units:3-hydroxy-4-cyclohexylbutyric acid, 3-hydroxy-10-undecenoic acid,3-hydroxy-8-nonenoic acid, and 3-hydroxy-6-heptenoic acid represented bythe following chemical formulas (31), (25), (26) and (27) respectively.

From the ¹H-NMR spectrum, it was confirmed that the proportion of theseunits was 37 mol % of the total three units, 3-hydroxy-10-undecenoicacid, 3-hydroxy-8-nonenoic acid, and 3-hydroxy-6-heptenoic acid, and 63mol % of 3-hydroxy-4-cyclohexylbutyric acid and others (straight chain3-hydroxyalkanoic acid having 4 to 12 carbon atoms, and3-hydroxyalka-5-enoic acid having 10 or 12 carbon atoms).

<Synthesis of Aliphatic Carboxy PHA by Oxidative Reaction (2)>

301 mg of polyhydroxyalkanoate obtained by pre-preparation 2 was addedinto a 200 mL round bottomed flask, and 20 mL of dichloromethane wasfurther added thereto, so that the above compound was dissolved. Theresultant product was left under ice bath cooling, and 3 mL of aceticacid and 541 mg of 18-crown-6-ether were then added thereto, followed bystirring. Thereafter, 430 mg of potassium permanganate was slowly addedthereto under ice bath cooling, and the mixture was stirred at roomtemperature for 20 hours. After completion of the reaction, water (50mL) and sodium hydrogen sulfite were added to the reaction product.Thereafter, 1.0 mol/L (1.0 N) hydrochloric acid was added thereto, sothat the mixed solution was adjusted to pH 1. Dichloromethane containedin the mixed solution was removed on an evaporator, and thereafter, apolymer contained in the solution was recovered. The recovered polymerwas washed with 100 mL of methanol and then with 100 mL of pure waterthree times, and thereafter the polymer was recovered. The recoveredpolymer was dried under reduced pressure, so as to obtain 184 mg of PHAof interest.

The average molecular weight of the obtained PHA was evaluated in thesame manner as in Example 1. As a result, number average molecularweight Mn=111,800, and weight average molecular weight Mw=272,800.

In order to specify the structure of the obtained PHA, an NMR analysiswas carried out under the same conditions as in Example 1. As a result,it was confirmed that the obtained PHA was a polyhydroxyalkanoatecopolymer, which comprised, as monomer units,3-hydroxy-4-cyclohexylbutyric acid, 3-hydroxy-9-carboxynonanoic acid,3-hydroxy-7-carboxyheptanoic acid, and 3-hydroxy-5-carboxyvaleric acidrepresented by the following chemical formula (31), (28), (29) and (30)respectively.

Moreover, in order to calculate the ratio of the units of the obtainedPHA, a carboxyl group located at the end of the side chain of PHA wasmethyl-esterified using trimethylsilyldiazomethane. 30 mg of PHA ofinterest was added into a 100 mL round bottomed flask, and 2.1 mL ofchloroform and 0.4 mL of methanol were then added thereto to dissolvethe PHA. 0.9 mL of 0.63 mol/L trimethylsilyldiazomethane-hexane solution(Tokyo Kasei) was added thereto, followed by stirring at roomtemperature for 30 minutes. After completion of the reaction, thesolvent was removed on an evaporator, and thereafter, a polymercontained in the solution was recovered. The recovered polymer waswashed with 50 mL of methanol, and then the polymer was recovered. Therecovered polymer was dried under reduced pressure, so as to obtain 31mg of PHA.

An NMR analysis was carried out by the same method as described above.As a result, it was confirmed from the ¹H-NMR spectrum that the ratio ofthe units was 9 mol % of the total three units,3-hydroxy-9-carboxynonanoic acid, 3-hydroxy-7-heptanoic acid, and3-hydroxy-5-valeric acid, and 91 mol % of 3-hydroxy-4-cyclohexylbutyricacid and others (straight chain 3-hydroxyalkanoic acid having 4 to 12carbon atoms, and 3-hydroxyalka-5-enoic acid having 10 or 12 carbonatoms).

The above method was scaled up, so as to obtain 50 g of PHA, which wasdenoted as PHA (2).

Example 3

<Pre-Preparation 3: Biosynthesis of ω-Alkene PHA (3)>

Three shaking flasks (volume: 2000 mL) were prepared. Thereafter, 0.5 wt% polypeptone (Wako Pure Chemical Industries, Ltd.), 4.8 mmol/L5-phenoxysulfanylvaleric acid, and 2 mmol/L 10-undecenoic acid weredissolved in 1000 mL of the above M9 medium, and the resultant solutionwas placed in each of the above 2000 mL shaking flasks and sterilized byan autoclave and cooled to room temperature. Pseudomonas cichorii YN2was shake-cultured for 8 hours in an M9 medium supplemented with 0.5%polypeptone, and 10 mL of the preculture was added to each of the aboveprepared media, and cultured at 30° C. for 38 hours. After completion ofthe culture, they were combined, and cells were recovered bycentrifugation. The obtained cells were washed with methanol and thendried. After weighing the dried cells, chloroform was added thereto, andthe mixture was stirred at 35° C. for 25 hours to extract a polymer. Thechloroform containing the extracted polymer was filtrated through a 0.45μm membrane filter, and the filtrate was concentrated using anevaporator. The condensate was then reprecipitated with cold methanol,to recover a polymer. Thereafter, the obtained polymer was dried underreduced pressure to obtain a polymer of interest.

As a result of weighing the obtained polymer, 1,934 mg of PHA (dryweight) was obtained in the present example.

The average molecular weight of the obtained PHA was evaluated in thesame manner as in Example 1. As a result, number average molecularweight Mn=430,000, and weight average molecular weight Mw=1,500,000.Moreover, in order to specify the structure of the obtained PHA, an NMRanalysis was carried out under the same conditions as in Example 1.

As a result, it was confirmed that the obtained PHA was apolyhydroxyalkanoate copolymer, which comprised, as monomer units,3-hydroxy-5-(phenylsulfanyl)valeric acid, 3-hydroxy-10-undecenoic acid,3-hydroxy-8-nonenoic acid, and 3-hydroxy-6-heptenoic acid represented bythe following chemical formulas (32), (25), (26) and (27) respectively.

From the ¹H-NMR spectrum, it was confirmed that the proportion of theseunits was 78 mol % of 3-hydroxy-5-(phenylsulfanyl)valeric acid, 19 mol %of the total three units of 3-hydroxy-10-undecenoic acid,3-hydroxy-8-nonenoic acid, and 3-hydroxy-6-heptenoic acid, and 3 mol %of others (straight chain 3-hydroxyalkanoic acid having 4 to 12 carbonatoms, and 3-hydroxyalka-5-enoic acid having 10 or 12 carbon atoms).

<Synthesis of Aliphatic Carboxy PHA by Oxidative Reaction (3)>

302 mg of polyhydroxyalkanoate obtained by pre-preparation 3 was addedinto a 200 mL round bottomed flask, and 20 mL of dichloromethane wasfurther added thereto, so that the above compound was dissolved. Theresultant product was left under ice bath cooling, and 3 mL of aceticacid and 1,154 mg of 18-crown-6-ether were then added thereto, followedby stirring. Thereafter, 917 mg of potassium permanganate was slowlyadded thereto under ice bath cooling, and the mixture was stirred atroom temperature for 19 hours. After completion of the reaction, water(50 mL) and 3,010 mg of sodium hydrogen sulfite were added to thereaction product. Thereafter, 1.0 N hydrochloric acid was added thereto,so that the mixed solution was adjusted to pH 1. Dichloromethanecontained in the mixed solution was removed on an evaporator, andthereafter, a polymer contained in the solution was recovered. Therecovered polymer was washed with 100 mL of methanol and then with 100mL of pure water three times, and thereafter the polymer was recovered.The recovered polymer was dried under reduced pressure, so as to obtain311 mg of PHA of interest.

The average molecular weight of the obtained PHA was evaluated in thesame manner as in Example 1. As a result, number average molecularweight Mn=62,000, and weight average molecular weight Mw=260,000.

In order to specify the structure of the obtained PHA, an NMR analysiswas carried out under the same conditions as in Example 1.

As a result, it was confirmed that the obtained PHA was apolyhydroxyalkanoate copolymer comprised of monomer units:3-hydroxy-5-(phenylsulfonyl)valeric acid, 3-hydroxy-9-carboxynonanoicacid, 3-hydroxy-7-carboxyheptanoic acid, and 3-hydroxy-5-carboxyvalericacid represented by the following chemical formulas (33), (28), (29) and(30) respectively.

Moreover, in order to calculate the ratio of the units of the obtainedPHA, a carboxyl group located at the end of the side chain of PHA wasmethyl-esterified using trimethylsilyldiazomethane.

30 mg of PHA of interest was added into a 100 mL round bottomed flask,and 2.1 mL of chloroform and 0.7 mL of methanol were then added theretoto dissolve the PHA. 0.5 mL of 2.0 mol/Ltrimethylsilyldiazomethane-hexane solution (Aldrich) was added thereto,followed by stirring at room temperature for 30 minutes. Aftercompletion of the reaction, the solvent was removed on an evaporator,and thereafter, a polymer contained in the solution was recovered. Therecovered polymer was washed with 50 mL of methanol, and then thepolymer was recovered. The recovered polymer was dried under reducedpressure, so as to obtain 31 mg of PHA.

An NMR analysis was carried out by the same method as described above.As a result, it was confirmed from the ¹H-NMR spectrum that the ratio ofthe units was 89 mol % of 3-hydroxy-5-(phenylsulfonyl)valeric acid, 8mol % of the total three units of 3-hydroxy-9-carboxynonanoic acid,3-hydroxy-7-heptanoic acid, and 3-hydroxy-5-valeric acid, and 3 mol % ofothers (straight chain 3-hydroxyalkanoic acid having 4 to 12 carbonatoms, and 3-hydroxyalka-5-enoic acid having 10 or 12 carbon atoms).

The above method was scaled up to obtain 50 g of PHA, which was denotedas PHA (3).

Example 4

<Pre-Preparation 4: Biosynthesis of ω-Alkene PHA (4)>

Three shaking flasks (volume: 2000 mL) were prepared. Thereafter, 0.5 wt% polypeptone (Wako Pure Chemical Industries, Ltd.), 6 mmol/L5-phenylvaleric acid, and 1.5 mmol/L 10-undecenoic acid were dissolvedin 1000 mL of the above M9 medium, and the resultant solution was placedin each of the above 2000 mL shaking flasks and sterilized by anautoclave and cooled to room temperature. Pseudomonas cichorii YN2 wasshake-cultured for 8 hours in an M9 medium supplemented with 0.5%polypeptone, and 10 mL of the preculture was added to each of the aboveprepared media, and cultured at 30° C. for 60 hours. After completion ofthe culture, they were combined, and cells were recovered bycentrifugation. The obtained cells were washed with methanol and thendried. After weighing the dried cells, chloroform was added thereto, andthe mixture was stirred at 25° C. for 72 hours to extract a polymer. Thechloroform containing the extracted polymer was filtrated through a 0.45μm membrane filter, and the filtrate was concentrated using anevaporator. The condensate was then reprecipitated with cold methanol,to recover a polymer. Thereafter, the obtained polymer was dried underreduced pressure to obtain a polymer of interest.

As a result of weighing the obtained polymer, 1,533 mg of PHA (dryweight) was obtained in the present example.

The average molecular weight of the obtained PHA was evaluated under thesame conditions as in Example 1. As a result, number average molecularweight Mn=72,000, and weight average molecular weight Mw=170,000.

Moreover, in order to specify the structure of the obtained PHA, an NMRanalysis was carried out under the same conditions as in Example 1.

As a result, it was confirmed that the obtained PHA was apolyhydroxyalkanoate copolymer comprised of monomer units:3-hydroxy-5-phenylvaleric acid, 3-hydroxy-10-undecenoic acid,3-hydroxy-8-nonenoic acid, and 3-hydroxy-6-heptenoic acid represented bythe following chemical formula (34), (25), (26) and (27) respectively.

From the ¹H-NMR spectrum, it was confirmed that the proportion of theseunits was 12 mol % of the total three units, 3-hydroxy-10-undecenoicacid, 3-hydroxy-8-nonenoic acid, and 3-hydroxy-6-heptenoic acid, 85 mol% of 3-hydroxy-5-phenylvaleric acid, and 3 mol % of others (straightchain 3-hydroxyalkanoic acid having 4 to 12 carbon atoms, and3-hydroxyalka-5-enoic acid having 10 or 12 carbon atoms).

<Synthesis of Aliphatic Carboxy PHA by Oxidative Reaction (4)>

1,002 mg of polyhydroxyalkanoate obtained by pre-preparation 4 was addedinto a 500 mL round bottomed flask, and 60 mL of acetone was furtheradded thereto, so that the above compound was dissolved. The resultantproduct was left under ice bath cooling, and 10 mL of acetic acid and537 mg of 18-crown-6-ether were then added thereto, followed bystirring. Thereafter, 429 mg of potassium permanganate was slowly addedthereto under ice bath cooling, and the mixture was stirred under icebath cooling for 2 hours, followed by further stirring at roomtemperature for 18 hours. After completion of the reaction, 40 mL ofethyl acetate, 30 mL of water, and 1,000 mg of sodium hydrogen sulfitewere added to the reaction product. Thereafter, 1.0 N hydrochloric acidwas added thereto, so that the mixed solution was adjusted to pH 1.A-polymer contained in the solution was extracted, and thereafter, thepolymer was recovered by solvent removal. The recovered polymer waswashed with 200 mL of pure water, then with 200 mL of methanol, and thenwith 200 mL of pure water three times. Thereafter, it was finally washedwith 200 mL of methanol, and the polymer was recovered. The thusrecovered polymer was dissolved in 10 mL of tetrahydrofuran, and thenusing a dialysis membrane (Spectra/Por Standard Regenerated CelluroseDialysis Membrane 3 from Spectrum), dialysis was carried out over dayand night in a 1 L beaker containing 500 mL of methanol. Thereafter, thepolymer contained in the dialysis membrane was recovered and thensubjected to reduced pressure drying, so as to obtain 953 mg of PHA ofinterest.

The average molecular weight of the obtained PHA was evaluated under thesame conditions as in Example 1. As a result, number average molecularweight Mn=43,000, and weight average molecular weight Mw=94,000.

In order to specify the structure of the obtained PHA, an NMR analysiswas carried out under the same conditions as in Example 1.

As a result, it was confirmed that the obtained PHA was apolyhydroxyalkanoate copolymer comprised of monomer units:3-hydroxy-5-phenylvaleric acid, 3-hydroxy-9-carboxynonanoic acid,3-hydroxy-7-carboxyheptanoic acid, and 3-hydroxy-5-carboxyvaleric acidrepresented by the following chemical formulas (34), (28), (29) and (30)repectively.

Moreover, in order to calculate the ratio of the units of the obtainedPHA, a carboxyl group located at the end of the side chain of PHA wasmethyl-esterified using trimethylsilyldiazomethane. 30 mg of PHA ofinterest was added into a 100 mL round bottomed flask, and 2.1 mL ofchloroform and 0.7 mL of methanol were then added thereto to dissolvethe PHA. 0.3 mL of 2.0 mol %/L trimethylsilyldiazomethane-hexanesolution (Aldrich) was added thereto, followed by stirring at roomtemperature for 30 minutes. After completion of the reaction, thesolvent was removed on an evaporator, and thereafter, a polymercontained in the solution was recovered. The recovered polymer waswashed with 50 mL of methanol, and then the polymer was recovered. Therecovered polymer was dried under reduced pressure, so as to obtain 30mg of PHA.

An NMR analysis was carried out under the same conditions as inExample 1. As a result, it was confirmed that the ratio of the units was86 mol % of 3-hydroxy-5-phenylvaleric acid, 9 mol % of the total threeunits, 3-hydroxy-9-carboxynonanoic acid, 3-hydroxy-7-carboxyheptanoicacid, and 3-hydroxy-5-carboxyvaleric acid, and 5 mol % of others(straight chain 3-hydroxyalkanoic acid having 4 to 12 carbon atoms, and3-hydroxyalka-5-enoic acid having 10 or 12 carbon atoms).

The above method was scaled up, so as to obtain 50 g of PHA, which wasdenoted as PHA (4).

Example 5

<Pre-Preparation 5: Biosynthesis of ω-Alkene PHA (5)>

Twenty shaking flasks (volume: 2000 mL) were prepared. Thereafter, 0.5wt % polypeptone (Wako Pure Chemical Industries, Ltd.), 6 mmol/L5-benzoylvaleric acid, and 1 mmol/L 10-undecenoic acid dissolved in 1000mL of the above M9 medium, and put in each of the above 2000 mL shakingflasks and sterilized by autoclaving and cooled to room temperature.Pseudomonas cichorii YN2 was shake-cultured for 8 hours in an M9 mediumsupplemented with 0.5% polypeptone, and 10 mL of the preculture wasadded to each of the above prepared flasks, and cultured at 30° C. for60 hours. After completion of the culture, they were combined, and cellswere recovered by centrifugation. The obtained cells were washed withmethanol and then dried. After weighing the dried cells, chloroform wasadded thereto, and the mixture was stirred at 25° C. for 72 hours toextract a polymer. The chloroform containing the extracted polymer wasfiltrated through a 0.45 μm membrane filter, and the filtrate wasconcentrated using an evaporator. The condensate was then reprecipitatedwith cold methanol, to recover a polymer. Thereafter, the obtainedpolymer was dried under reduced pressure to obtain a polymer ofinterest.

As a result of weighing the obtained polymer, 1,027 mg of PHA (dryweight) was obtained in the present example.

The average molecular weight of the obtained PHA was evaluated under thesame conditions as in Example 1. As a result, number average molecularweight Mn=120,000, and weight average molecular weight Mw=370,000.

Moreover, in order to specify the structure of the obtained PHA, an NMRanalysis was carried out under the same conditions as in Example 1.

As a result, it was confirmed that the obtained PHA was apolyhydroxyalkanoate copolymer comprised of monomer units:3-hydroxy-5-benzoylvaleric acid, 3-hydroxy-10-undecenoic acid,3-hydroxy-8-nonenoic acid), and 3-hydroxy-6-heptenoic acid representedby the following chemical formulas (35), (25), (26) and (27)respectively.

From the ¹H-NMR spectrum, it was confirmed that the proportion of theseunits was 11 mol % of the total three units, 3-hydroxy-10-undecenoicacid, 3-hydroxy-8-nonenoic acid, and 3-hydroxy-6-heptenoic acid, 82 mol% of 3-hydroxy-5-benzoylvaleric acid, and 7 mol % of others (straightchain 3-hydroxyalkanoic acid having 4 to 12 carbon atoms, and3-hydroxyalka-5-enoic acid having 10 or 12 carbon atoms).

1,003 mg of polyhydroxyalkanoate obtained by pre-preparation 5 was addedinto a 500 mL round bottomed flask, and 20 mL of dichloromethane wasfurther added thereto, so that the above compound was dissolved. Theresultant product was left under ice bath cooling, and 10 mL of aceticacid and 410 mg of 18-crown-6-ether were then added thereto, followed bystirring. Thereafter, 327 mg of potassium permanganate was slowly addedthereto under ice bath cooling, and the mixture was stirred under icebath cooling for 2 hours, followed by further stirring at roomtemperature for 18 hours. After completion of the reaction, 100 mL ofwater, and 1,000 mg of sodium hydrogen sulfite were added to thereaction product. Thereafter, 1.0 N hydrochloric acid was added thereto,so that the mixed solution was adjusted to pH 1. Dichloromethanecontained in the mixed solution was removed on an evaporator, and then apolymer contained in the solution was recovered. The recovered polymerwas washed with 200 mL of pure water, then with 200 mL of methanol, andthen with 200 mL of pure water three times. Thereafter, it was finallywashed with 200 mL of methanol, and the polymer was recovered. The thusrecovered polymer was dissolved in 10 mL of tetrahydrofuran, and thenusing a dialysis membrane (Spectra/Por Standard Regenerated CelluroseDialysis Membrane 3 from Spectrum), dialysis was carried out over dayand night in a 1 L beaker containing 500 mL of methanol. Thereafter, thepolymer contained in the dialysis membrane was recovered and thensubjected to reduced pressure drying, so as to obtain 948 mg of PHA ofinterest.

The average molecular weight of the obtained PHA was evaluated under thesame conditions as in Example 1. As a result, number average molecularweight Mn=76,000, and weight average molecular weight Mw=235,000.

In order to specify the structure of the obtained PHA, an NMR analysiswas carried out under the same conditions as in Example 1.

As a result, it was confirmed that the obtained PHA was apolyhydroxyalkanoate copolymer comprised of monomer units:3-hydroxy-5-benzoylvaleric acid, 3-hydroxy-9-carboxynonanoic acid,3-hydroxy-7-carboxyheptanoic acid, and 3-hydroxy-5-carboxyvaleric acidrepresented by the following chemical formulas (35), (28), (29) and (30)respectively.

Moreover, in order to calculate the ratio of the units of the obtainedPHA, a carboxyl group located at the end of the side chain of PHA wasmethyl-esterified using trimethylsilyldiazomethane.

30 mg of PHA of interest was added into a 100 mL round bottomed flask,and 2.1 mL of chloroform and 0.7 mL of methanol were then added theretoto dissolve the PHA. 0.3 mL of 2.0 mol %/Ltrimethylsilyldiazomethane-hexane solution (Aldrich) was added thereto,followed by stirring at room temperature for 30 minutes. Aftercompletion of the reaction, the solvent was removed on an evaporator,and thereafter, a polymer contained in the solution was recovered. Therecovered polymer was washed with 50 mL of methanol, and then thepolymer was recovered. The recovered polymer was dried under reducedpressure, so as to obtain 29 mg of PHA.

An NMR analysis was carried out under the same conditions as inExample 1. As a result, it was confirmed that the ratio of the units was84 mol % of 3-hydroxy-5-benzoylvaleric acid, 9 mol % of the total threeunits, 3-hydroxy-9-carboxynonanoic acid, 3-hydroxy-7-carboxyheptanoicacid, and 3-hydroxy-5-carboxyvaleric acid, and 7 mol % of others(straight chain 3-hydroxyalkanoic acid having 4 to 12 carbon atoms, and3-hydroxyalka-5-enoic acid having 10 or 12 carbon atoms).

The above method was scaled up, so as to obtain 50 g of PHA, which wasdenoted as PHA (5).

Example 6

5.0 g of polypeptone (Wako Pure Chemical Industries, Ltd.) was added to1,000 mL of the above M9 medium, and 5-phenylvaleric acid and sebacicacid monomethyl ester were also added thereto to final concentrations of4 mmol/L and 1 mmol/L, respectively. The mixture was placed in a 2,000mL shaking flask, sterilized by autoclaving and cooled to roomtemperature. Pseudomonas cichorii YN2 was shake-cultured for 8 hours inan M9 medium supplemented with 0.5% polypeptone, and 5 mL of thepreculture was added to each of the above prepared flasks, and culturedat 30° C. for 40 hours. After completion of the culture, they werecombined, and cells were recovered by centrifugation. The obtained cellswere washed with methanol and then dried. After weighing the driedcells, chloroform was added thereto, and the mixture was stirred at 50°C. for 48 hours to extract a polymer. The chloroform containing theextracted polymer was filtrated, and the filtrate was concentrated usingan evaporator. The condensate was then reprecipitated with coldmethanol, to recover a polymer. Thereafter, the obtained polymer wasdried under reduced pressure to obtain a polymer of interest. As aresult of weighing the obtained polymer, 671 mg of PHA (dry weight) wasobtained in the present example.

The structure of the obtained polymer was determined by the followingmethylation-GC/MS method. That is to say, 5 mg of polymer was dissolvedin 2 mL of chloroform, 2 mL of methanol-3% sulfuric acid solution wasfurther added thereto, and a reaction was carried out under reflux at100° C. for 3.5 hours. After completion of the reaction, the reactionsolution was cooled to room temperature, and 10 mL of deionized waterwas added thereto followed by stirring and separation. The organic layerwas dehydrated with magnesium sulfate (anhydride), and thereafter, thereaction solution was subjected to measurement with a gaschromatograph-mass spectrometer (GC/MS: Shimadzu QP-5050A, column:DB-WAXETR 0.32 mm×30 m). Three main peaks were observed at 35.6 minutes,38.0 minutes, and 45.8 minutes. As a result of measuring the massspectrum (MS) of each peak, it was found that the peak at 35.6 minuteswas derived from the unit represented by chemical formula (36):

that the peak at 38.0 minutes was derived from the unit represented bychemical formula (34):

and that the peak at 45.8 minutes was derived from the unit representedby chemical formula (37):

Moreover, the ratio of the units calculated from the peak area ratio ofTIC was 12.0%, 77.7%, and 6.7%, respectively.

The average molecular weight of the obtained PHA was evaluated under thesame conditions as in Example 1. As a result, number average molecularweight Mn=81,000, and weight average molecular weight Mw=159,000.

The above method was scaled up, so as to obtain 50 g of PHA, which wasdenoted as PHA (6).

Example 7

Two shaking flasks (volume: 2,000 mL) were prepared. Thereafter, 0.5 wt% polypeptone (Wako Pure Chemical Industries, Ltd.), 4 mmol/L5-phenoxyvaleric acid, and 1 mmol/L dodecanedioic acid monoethyl esterwere dissolved in 1,000 mL of the above M9 medium, and the resultantsolution was placed in each of the above 2,000 mL shaking flasks,sterilized by autoclaving, and cooled to room temperature. 5 mL of theculture solution of Pseudomonas cichorii YN2 strain that had previouslybeen subjected to shaking culture at 30° C. for 8 hours in an M9 mediumcontaining 0.5% polypeptone was added to each of the above preparedmedia, cultured at 30° C. for 41 hours. After completion of the culture,cells were recovered by centrifugation, and the obtained cells werewashed with methanol and then lyophilized. After weighing the driedcells, chloroform was added thereto, and the mixture was stirred at 50°C. for 48 hours to extract polymer. The chloroform containing theextracted polymer was filtrated, and the filtrate was concentrated usingan evaporator. The precipitated and solidified portion was collectedwith cold methanol, and dried under reduced pressure, so as to obtain apolymer of interest. As a result of weighing the obtained polymer, 680mg of PHA (dry weight) was obtained in the present example.

The average molecular weight of the obtained PHA was evaluated under thesame conditions as in Example 1. As a result, number average molecularweight Mn=69,000, and weight average molecular weight Mw=135,000.

Moreover, in order to specify the structure of the obtained PHA, an NMRanalysis was carried out under the same conditions as in Example 1.

As a result, it was confirmed that the obtained PHA was apolyhydroxyalkanoate copolymer, which comprised 74 mol % of3-hydroxy-5-phenoxyvaleric acid, 17 mol % of the total three units,3-hydroxy-11-ethoxycarbonyl undecanoic acid, 3-hydroxy-9-ethoxycarbonylnonanoic acid, and 3-hydroxy-7-ethoxycarbonyl heptanoic acid representedby the following chemical formulas (24), (38), (39) and (40)respectively, and 9 mol % of others (straight chain 3-hydroxyalkanoicacid having 4 to 12 carbon atoms, and 3-hydroxyalka-5-enoic acid having10 or 12 carbon 10 atoms).

The above method was scaled up, so as to obtain 50 g of PHA, which wasdenoted as PHA (7).

Compounds obtained in Examples 1 to 7 were defined as Example compounds1 to 7, and the compounds were used in Example 8 and later examples.

Then, charge controlling agents produced in the same manner as inExamples 1 to 7 by methods selected from those of the present inventionwere used to produce various kinds of toners, and the toners wereevaluated.

Example 8

First, an aqueous Na₃PO₄ solution was added in a 2 liter four-neckedflask equipped with a high-speed stirring apparatus TK-Homomixer, andwas heated at 60° C., keeping rotation speed at 10,000 rpm. An aqueousCaCl₂ solution was slowly added therein to prepare a water baseddispersing medium containing a very small low-water solubilitydispersant Ca₃(PO₄)₂.

On the other hand, the following compositions were dispersed for 3 hoursusing a ball mill, followed by adding therein 10 parts by mass ofrelease agent (ester wax) and 10 parts by mass of2,2′-azobis(2,4-dimethylvaleronitrile) as a polymerization initiator toprepare a polymerizable monomer composition. styrene monomer 82 partsethylhexyl acrylate monomer 18 parts divinylbenzene monomer 0.1 partscyan coloring agent (C.I. Pigment Blue 15) 6 parts oxidized polyethyleneresin (molecular weight 3200, 5 parts acid number 8) exemplary compound(1) 2 parts.

Then, the polymerizable monomer composition obtained as described abovewas put in the above water based dispersant system to form particles ata rotation speed of 10,000 rpm. Thereafter, reaction was carried out at65° C. for 3 hours stirring with paddle blades, and was thereafterpolymerized at 80° C. for 6 hours to complete the polymerizationreaction. After the reaction was completed, the suspension was cooled,and an acid was added therein to dissolve the low-water solubilitydispersant Ca₃(PO₄)₂, followed by filtering, rinsing and drying thesolution to obtain blue polymerized particles (1). The particle size ofthe obtained blue polymerized particles (1) measured using CoulterCounter Multisizer (from Coulter Co.) was 6.8 μm (weight averageparticle size), and the ratio of fines (the abundance ratio of particleswith the size of 3.17 μm or smaller in the number distribution) was 5.1%by number.

As a fluidity improver, 1.3 parts by mass of hydrophobic silica finepowder (BET: 270 m²/g) treated with hexamethyl disilazane wereexternally added to 100 parts by mass of blue polymerized particles(1)prepared as described above by dry-mixing using a Henshel mixer, wherebya blue toner (1) of this Example was obtained. In addition, 7 parts bymass of blue toner (1) were mixed with 93 parts by mass resin-coatedmagnetic ferrite carrier (average particle size: 45 μm) to prepare atwo-component type blue developer (1) for magnetic brush development.

Example 9 to 14

Blue toners (2) to (7) of Examples 9 to 14 were obtained in the samemanner as in Example 8 except that 2.0 parts by mass of exemplarycompounds (2)-(7) were used in place of the exemplary compound (1). Theproperties of the toner were measured in the same manner as in Example8, and the results thereof are shown in Table 1. In addition,two-component type blue developers (2) to (7) were obtained in the samemanner as in Example 8 using this toner.

Comparative Example 1

A blue toner (8) of Comparative Example 1 was obtained in the samemanner as in Example 8 except that no exemplary compound was used. Theproperties of this toner were measured in the same manner as in Example8, and the results thereof are shown in Table 1. In addition, atwo-component type blue developer (8) of Comparative Example 1 wasobtained in the same manner as in Example 8 using this toner.

<Evaluation>

For the two-component type blue developers (1) to (7) obtained in theExamples 6 to 14 and the two-component type blue developer (8) obtainedin the Comparative Example 1, the charge levels of toners after stirringfor 10 and 300 seconds were measured under conditions of normaltemperature and normal humidity (25° C., 60% RH) and high temperatureand high humidity (30° C., 80% RH) using the previously described methodof measuring charge levels. Then, numbers from measurement values oftwo-component blow-off charge levels were rounded off to the firstdecimal place to make evaluations according to the following criteria.The results are shown together in Table 1.

[Electrifiability]

AA: Excellent (−20 μC/g or lower)

A: Good (−19.9 to −10.0 μC/g)

B: Usable (−9.9 to −5.0 μC/g)

C: Unusable (−4.9 μC/g or higher)

Examples 15 to 19

Yellow toners (1) to (7) of Examples 15 to 19 were obtained in the samemanner as in Example 8 except that 2.0 parts by mass of exemplarycompounds (1) to (7) were used, and a yellow coloring agent (Hansayellow G) was used in place of the cyan coloring agent. The propertiesof these toners were measured in the same manner as in Example 8, andthe results thereof are shown together in Table 1. In addition,two-component type yellow developers (1) to (7) were obtained in thesame manner as in Example 8 using these toners.

Comparative Example 2

A yellow toner (8) of Comparative Example 2 was obtained in the samemanner as in Example 8 except that no charge controlling agent was used,and that the yellow coloring agent (Hansa yellow G) was used in place ofthe cyan coloring agent. The properties of this toner were measured inthe same manner as in Example 8, and the results thereof are showntogether in Table 1. In addition, a two-component type yellow developer(8) of Comparative Example 2 was obtained in the same manner as inExample 8 using this toner.

<Evaluation>

For the two-component type yellow developers (1) to (7) obtained in theExamples 15 to 21 and the two-component type yellow developer (8)obtained in the Comparative Example 2, the charge levels of toners afterstirring for 10 and 300 seconds were measured under conditions of normaltemperature and normal humidity (25° C., 60% RH) and high temperatureand high humidity (30° C., 80% RH) using the previously described methodof measuring charge levels. Then, numbers from measurement values oftwo-component blow-off charge levels were rounded off to the firstdecimal place to make evaluations according to the same criteria as inthe Examples 8 to 14. The results are shown together in Table 1.

Examples 22 to 28

Black toners (1) to (7) of Examples 22 to 28 were obtained in the samemanner as in Example 8 except that 2.0 parts by mass of exemplarycompounds (1) to (7) were used, and a carbon black (DBP oil absorption110 mL/100 g) was used in place of the cyan coloring agent. Theproperties of these toners were measured in the same manner as inExample 8, and the results thereof are shown together in Table 1. Inaddition, two-component type black developers (1) to (7) were obtainedin the same manner as in Example 8 using these toners.

Comparative Example 3

A black toner (8) of Comparative Example 3 was obtained in the samemanner as in Example 8 except that no exemplary compound was used, andthat the carbon black (DBP oil absorption 110 mL/100 g) was used inplace of the cyan coloring agent. The properties of this toner weremeasured in the same manner as in Example 8, and the results thereof areshown together in Table 1. In addition, a two-component type blackdeveloper (8) of Comparative Example 3 was obtained in the same manneras in Example 8 using this toner.

<Evaluation>

For the two-component type black developers (1) to (7) obtained in theExamples 22 to 28 and the two-component type black developer (8)obtained in the Comparative Example 3, the charge levels of toners afterstirring for 10 and 300 seconds were measured under conditions of normaltemperature and normal humidity (25° C., 60% RH) and high temperatureand high humidity (30° C., 80% RH) using the previously described methodof measuring charge levels. Then, numbers from measurement values oftwo-component blow-off charge levels were rounded off to the firstdecimal place to make evaluations according to the same criteria as inExamples 8 to 14. The results are shown together in Table 1. TABLE 1Particle size distribution and electrification characteristic of tonersof various colors Particle size Electrifiability distribution Normaltemperature High temperature Weight and normal and high humidity averageRatio of humidity (Q/M) (Q/M) particle fines Stirring Stirring StirringStirring Compound Toner size (% by for 10 for 300 for 10 for 300Examples number Number: (μm) number) seconds seconds seconds seconds 8 1Blue 1 6.8 5.1 AA AA AA AA 9 2 Blue 2 6.9 5.4 AA AA AA AA 10 3 Blue 36.8 5.2 AA AA AA AA 11 4 Blue 4 7.0 5.0 AA AA AA AA 12 5 Blue 5 6.8 4.8AA AA AA AA 13 6 Blue 6 6.7 4.7 AA AA AA AA 14 7 Blue 7 6.9 5.0 AA AA AAAA 15 1 Yellow 1 7.0 5.6 AA AA AA AA 16 2 Yellow 2 6.9 5.4 AA AA AA AA17 3 Yellow 3 6.8 5.5 AA AA AA AA 18 4 Yellow 4 6.8 5.4 AA AA AA AA 19 5Yellow 5 7.1 5.7 AA AA AA AA 20 6 Yellow 6 6.9 4.9 AA AA AA AA 21 7Yellow 7 7.0 5.2 AA AA AA AA 22 1 Black 1 7.1 5.5 AA AA AA AA 23 2 Black2 7.0 5.5 AA AA AA AA 24 3 Black 3 6.8 5.3 AA AA AA AA 25 4 Black 4 6.95.5 AA AA AA AA 26 5 Black 5 7.1 5.4 AA AA AA AA 27 6 Black 6 6.7 4.8 AAAA AA AA 28 7 Black 7 6.8 4.9 AA AA AA AA Comparative — Blue 8 7.0 5.2 CC C C Example 1 Comparative — Yellow 8 7.2 4.9 C C C C Example 2Comparative — Black 8 6.9 5.3 C B C B Example 3

Example 29

The following composition were mixed, and were melt-kneaded by a twenscrew extruder (L/D=30): stylene-butylacrylate copolymer resin 100 parts(glass transition temperature 70° C.) magenta pigment (C.I. Pigment Red114 5 parts exemplary compound (1) 2 parts.

The resulting mixture was cooled, roughly ground by a hammer mill,finely ground by a jet mill, and then classified to obtain magentacoloring particles (1) by a grinding method. For the particle size ofthe magenta coloring particles (1), the weight average particle size was6.8 μm and the ratio of fines was 5.0% by number.

As a fluidity improver, 1.5 parts by mass of hydrophobic silica finepowder (BET: 250 m²/g) treated with hexamethyl disilazane were dry-mixedwith 100 parts by mass of the magenta coloring particles (1) by aHenshel mixer, whereby a magenta toner (1) of this Example was obtained.In addition, 7 parts by mass of the resulting magenta toner (1) weremixed with 93 parts by mass resin-coated magnetic ferrite carrier(average particle size: 45 μm) to prepare a two-component type magentadeveloper (1) for magnetic brush development.

Examples 30 to 35

Magenta toners (2) to (7) of Examples 30 to 35 were obtained in the samemanner as in Example 29 except that 2.0 parts by mass of exemplarycompound (1) was replaced by each of exemplary compounds (2) to (7). Theproperties of this toner were measured in the same manner as in Example8, and the results thereof are shown in Table 2. In addition,two-component type magenta developers (2) to (7) were obtained in thesame manner as in Example 29 using this toner.

Comparative Example 4

A magenta toner (16) of Comparative Example 4 was obtained in the samemanner as in Example 29 except that no exemplary compound was used. Theproperties of this toner were measured in the same manner as in Example8, and the results thereof are shown together in Table 2. In addition, atwo-component type magenta developer (16) of Comparative Example 4 wasobtained in the same manner as in Example 29 using this toner.

<Evaluation>

For the two-component type magenta developers (9) to (15) obtained inthe Examples 29 to 35 and the two-component type magenta developer (16)obtained in the Comparative Example 4, the charge levels of toners afterstirring for 10 and 300 seconds were measured under conditions of normaltemperature and normal humidity (25° C., 60% RH) and high temperatureand high humidity (30° C., 80% RH) using the previously described methodof measuring charge levels. Then, numbers from measurement values oftwo-component blow-off charge levels were rounded off to the firstdecimal place to make evaluations according to the following criteria.The results are shown together in Table 2.

[Electrifiability]

AA: Excellent (−20 μC/g or lower)

A: Good (−19.9 to −10.0 μC/g)

B: Usable (−9.9 to −5.0 μC/g)

C: Unusable (−4.9 μC/g or higher)

Examples 36 to 42

Black toners (9) to (15) of Examples 36 to 42 were obtained in the samemanner as in Example 29 except that 2.0 parts by mass of exemplarycompounds (1) to (7) were used, and a carbon black (DBP oil absorption110 mL/100 g) was used in place of the magenta pigment. The propertiesof these toners were measured in the same manner as in Example 8, andthe results thereof are shown together in Table 2. In addition,two-component type black developers (9) to (15) were obtained in thesame manner as in Example 29 using these toners.

Comparative Example 5

A black toner (16) of Comparative Example 5 was obtained in the samemanner as in Example 29 except that no exemplary compound was used, andthat the carbon black (DBP oil absorption 110 mL/100 g) was used inplace of the magenta pigment. The properties of this toner were measuredin the same manner as in Example 8, and the results thereof are showntogether in Table 2. In addition, a two-component type black developer(16) of Comparative Example 5 was obtained in the same manner as inExample 29 using this toner.

<Evaluation>

For the two-component type black developers (9) to (15) obtained in theExamples 36 to 42 and the two-component type black developer (16)obtained in the Comparative Example 5, the charge levels of toners afterstirring for 10 and 300 seconds were measured under conditions of normaltemperature and normal humidity (25° C., 60% RH) and high temperatureand high humidity (30° C., 80% RH) using the previously described methodof measuring charge levels. Then, numbers from measurement values oftwo-component blow-off charge levels were rounded off to the firstdecimal place to make evaluations according to the same criteria as inExamples 29 to 35. The results are shown together in Table 2. TABLE 2Particle size distribution and electrification characteristic of tonersof various colors Particle size Electrifiability distribution Normaltemperature High temperature Weight and normal and high humidity averageRatio of humidity (Q/M) (Q/M) particle fines Stirring Stirring StirringStirring Compound Toner size (% by for 10 for 300 for 10 for 300Examples number Number: (μm) number) seconds seconds seconds seconds 291 Red 1 6.8 5.2 AA AA AA AA 30 2 Red 2 7.1 5.4 AA AA AA AA 31 3 Red 36.7 5.3 AA AA AA AA 32 4 Red 4 7.0 5.1 AA AA AA AA 33 5 Red 5 7.1 5.5 AAAA AA AA 34 6 Red 6 6.7 5.1 AA AA AA AA 35 7 Red 7 6.9 5.4 AA AA AA AA36 1 Black 9 7.1 5.3 AA AA AA AA 37 2 Black 10 7.0 5.3 AA AA AA AA 38 3Black 11 6.9 5.1 AA AA AA AA 39 4 Black 12 7.2 5.5 AA AA AA AA 40 5Black 13 7.1 5.5 AA AA AA AA 41 6 Black 14 7.0 5.0 AA AA AA AA 42 7Black 15 6.8 4.9 AA AA AA AA Comparative — Red 16 7.1 5.1 C C C CExample 4 Comparative — Black 16 7.0 5.7 C B C B Example 5

Example 43

The following composition was prepared: polyester resin 100 parts carbonblack (DBP absorption 110 mL/100 g) 5 parts exemplary compound (1) 2parts.

The polyester resin was synthesized as follows: 751 parts of bisphenol Apropylene oxide 2 mol adduct, 104 parts of terephtalic acid and 167parts of trimellitic anhydride were poly-condensed with two parts ofdibutyltin oxide as a catalyst to obtain a polyester resin having asoftening point of 125° C.

The above described composition was mixed, and melt-kneaded by a twenscrew extruder (L/D=30). The resulting mixture was cooled, wasthereafter roughly ground by a hammer mill and finely ground by a jetmill, and was thereafter classified to obtain black coloring particles(17) by a grinding method. For the particle size of the black coloringparticles (17), the weight average particle size was 7.6 μm and theratio of fines was 4.7% by number.

As a fluidity improver, 1.5 parts by mass of hydrophobic silica finepowder (BET: 250 m²/g) treated with hexamethyl disilazane were dry-mixedwith 100 parts by mass of the black coloring particles (17) by a Henshelmixer to obtain a black toner (17) of this example. In addition, sevenparts by mass of the resulting black toner (17) were mixed with 93 partsby mass of resin-coated magnetic ferrite carrier (average particle size:44 μm) to prepare a two-component type black developer (17) for magneticbrush development.

Examples 44 to 49

Black toners (18) to (23) of Examples 44 to 49 were obtained in the samemanner as in Example 43 except that 2.0 parts by mass of exemplarycompounds (2) to (7) were used in place of exemplary compound (1). Theproperties of these toners were measured in the same manner as inExample 8, and the results thereof are shown in Table 3. In addition,two-component type black developers (18) to (23) were obtained in thesame manner as in Example 43 using this toner.

Comparative Example 6

A black toner (24) of Comparative Example 6 was obtained in the samemanner as in Example 43 except that no exemplary compound was used. Theproperties of this toner were measured in the same manner as in Example8, and the results thereof are shown in Table 3. In addition, atwo-component type black developer (24) of Comparative Example 6 wasobtained in the same manner as in Example 43 using this toner.

<Evaluation>

For the two-component type black developers (17) to (23) obtained in theExamples 43 to 49 and the two-component type black developer (24)obtained in the Comparative Example 6, the charge levels of toners afterstirring for 10 and 300 seconds were measured under conditions of normaltemperature and normal humidity (25° C., 60% RH) and high temperatureand high humidity (30° C., 80% RH) using the previously described methodof measuring charge levels. Then, numbers from measurement values oftwo-component blow-off charge levels were rounded off to the firstdecimal place to make evaluations according to the following criteria.The results are shown together in Table 3.

[Electrifiability]

AA: Excellent (−20 μC/g or lower)

A: Good (−19.9 to −10.0 μC/g)

B: Usable (−9.9 to −5.0 μC/g)

C: Unusable (−4.9 μC/g or higher)

[Table 3] TABLE 3 Particle size distribution and electrificationcharacteristic of tonerss of various colors Particle sizeElectrifiability distribution Normal temperature High temperature Weightand normal and high humidity average Ratio of humidity (Q/M) (Q/M)particle fines Stirring Stirring Stirring Stirring Compound Toner size(% by for 10 for 300 for 10 for 300 Examples number Number: (μm) number)seconds seconds seconds seconds 43 1 Black 17 7.6 4.7 AA AA AA AA 44 2Black 18 7.7 5.1 AA AA AA AA 45 3 Black 19 7.6 4.8 AA AA AA AA 46 4Black 20 7.5 5.2 AA AA AA AA 47 5 Black 21 7.9 5.7 AA AA AA AA 48 6Black 22 7.6 5.4 AA AA AA AA 49 7 Black 23 7.8 5.8 AA AA AA AAComparative — Black 24 7.5 4.9 C B C B Example 6

Examples 50 to 76 and Comparative Examples 7 to 12

First, an image forming apparatus used in the image formation methods ofExamples 50 to 76 and Comparative Examples 7 to 12 will be described.FIG. 1 is a schematic explanatory view of the cross section of an imageforming apparatus for carrying out the image formation methods ofExamples and Comparative Examples of the present invention. Aphotosensitive drum 1 shown in FIG. 1 has a photosensitive layer 1 ahaving an organic photo semiconductor on a substrate 1 b, and isconfigured to rotate in the direction indicated by the arrow, and itssurface is electrically charged at a potential of about −600 V by acharge roller 2 being a charge member situated opposite to thephotosensitive drum 1 and contacting and rotating with the drum. Asshown in FIG. 1, the charge roller 2 has a metal core 2 b covered with aconductive elastic layer 2 a.

Next, the photosensitive drum 1 with its surface electrically charged isexposed to light 3 and at this time, on/off operations are performed onthe photosensitive by a polygon mirror according to digital imageinformation, whereby an electrostatic latent image with the potential ofthe exposed area being −100 V and the potential of the dark area being−600 V is formed. Subsequently, this electrostatic latent image on thephotosensitive drum 1 is reverse-developed and thereby actualized usinga plurality of development apparatuses 4-1, 4-2, 4-3 and 4-4, and thustoner imaged are formed on the photosensitive drum 1. At that time, thetwo-component type developers obtained in the above Examples andComparative Examples were respectively used as a developer to form atoner image with a yellow toner, a magenta toner, a cyan toner or ablack toner. FIG. 2 is an enlarged sectional view of principal parts ofdevelopment apparatuses 4 for two-component type developers used at thattime.

Then, the toner images on the photosensitive drum 1 are transferred toan intermediate transfer member 5 contacting and rotating with thephotosensitive drum 1. As a result, a four-color overlapped toner imageis formed on the intermediate transfer member 5. A non-transferred tonerremaining on the photosensitive drum 1 without being transferred iscollected in a residual toner container 9 by a cleaning member 8.

The intermediate transfer member 5 is constituted by a metal core 5 b asa support and an elastic layer 5 a provided thereon as shown in FIG. 1.In this Example, the intermediate member 5 having the metal core 5 bcoated with the elastic layer 56 with a carbon black as a conductivityproducer sufficiently dispersed in nitrile-butadiene rubber (NBR) wasused. The degree of hardness of the elastic layer 56 measured inaccordance with “JIS K-6301” was 30 degrees, and the volume resistivitywas 10⁹ Ω.cm. The level of transfer current required for transferringthe image from the photosensitive drum 1 to the intermediate transfermember 5 is about 5 μA, and this level of current was obtained by addinga voltage of +500 V to the metal core 5 b.

The four-color toner-developed image formed on the intermediate transfermember 5 is transferred to a transferring material such as paper by atransfer roller 7, and is thereafter fixed by a heat-fixation apparatusH. The transfer roller 7 is provided thereon the core metal 7 b with theoutside diameter of 10 mm on which an elastic layer 7 a is by coatingethylene-propylene-diene based tridimensional copolymer (EPDM) foamdispersing carbon sufficiently therein as a conductivity producingmaterial. The layer had a volume specific resistance of 10⁶Ω.cm and ahardness degree of 35° as measured in accordance with “JIS K-6301”. Inaddition, a voltage was applied to this transfer roller 7 to pass atransfer current of 15 μA therethrough.

In the apparatus shown in FIG. 1, a fixation apparatus of heat roll typehaving no oil coating mechanism shown in FIGS. 1 and 2 was used in theheat-fixation apparatus H. The both upper and lower rollers of thefixation apparatus used here had surface layers made of fluorine basedresin. In addition, the diameter of the roller was 60 mm. The fixationtemperature for fixation was 160° C., and the nipping width was set at 7mm. Furthermore, a transfer residual toner on the photosensitive drum 1,which was collected by cleaning and transported to a developing deviceby a reuse mechanism for reuse.

<Evaluation>

Two-component type developers produced using the toners of Examples 8 to49 and two-component type developers produced using toners ofComparative Examples 1 to 6 were used, respectively, to perform printouttesting at a printout rate of 8 sheets (A4 size) per minute in amonochromatic intermittent mode (namely a mode in which the developingdevice is stopped for 10 seconds for each printout to accelerate thedeterioration of a toner in a preliminary operation during restart ofthe device), supplying the developer, at a normal temperature and normalhumidity (25° C., 60% RH) and a high temperature and high humidity (30°C., 80% RH) under the conditions described above, and resulting printoutimages were evaluated for the following items. The evaluation resultsare shown together in Table 4.

[Evaluation of Printout Images]

1. Image Density

Images were printed out on a predetermined number of normal copyingpapers (75 g/m²), and the image density was evaluated according to thelevel at which the density of the image from the final printout wasretained with respect to the density of the initial image. Here, for themeasurement of image density, a Macbeth reflective densitometer (fromMacbeth Co., Ltd.) was used to measure a density relative to that of theprintout image of a white ground of which original density was 0.00.

AA: Excellent (image density from the final printout is 1.40 or greater)

A: Good (image density from the final printout is 1.35 or greater andlower than 1.40)

B: Usable (image density from the final printout is 1.00 or greater andlower than 1.35)

C: Unusable (image density from the final printout is lower than 1.00)

2. Image Fog

Images were printed out on a predetermined number of normal copyingpapers (75 g/m²), and the image fog was evaluated with a solid whiteimage of the final printout. Specifically, the evaluation was made asfollows: the worst value of the reflective density of the white groundafter printing and the average reflective density of the paper beforeprinting, as measured using a reflective densitometer (ReflectometerODEL TC-6DS from Tokyo Denshoku Co., Ltd.), were defined as Ds and Dr,respectively, and (Ds-Dr) was calculated from these values as a foglevel to make an evaluation according to the following criteria.

AA: Excellent (fog level is 0% or higher and lower than 1.5%)

A: Good (fog level is 1.5% or higher and lower than 3.0%)

B: Usable (fog level is 3.0% or higher and lower than 5.0%)

C: Unusable (fog level is higher than 5.0%)

3. Transferability

Solid black images were printed out on a predetermined number of normalcopying papers (75 g/m²), and the image dislocation level of the imagefrom the final printout was visually observed to make an evaluationaccording to the following criterion.

AA: Excellent (almost not observed)

A: Good (slightly observed)

B: Usable

C: Unusable

In addition, in Examples 50 to 76 and Comparative Examples 7 to 12,occurrences of scars and sticking residual toners on the surfaces of thephotosensitive drum and the intermediate transfer member, and theirinfluence on printout images (matching with the image forming apparatus)were visually evaluated after 5000 images were outputted, and as aresult, scars and sticking residual toners on the surfaces of thephotosensitive drum and the intermediate transfer member were notobserved at all, and thus matching with the image forming apparatus wasexcellent. On the other hand, in the system using two-component typedevelopers of Comparative Examples 7 to 12, sticking toners and surfacescars were observed on the surface of the intermediate transfer member,and there was a problem in matching with image formation apparatus suchthat longitudinal striped defects occurred in the image. TABLE 4 Two-Normal temperature and normal High temperature and high componenthumidity humidity type Image Image Image Image Examples developerdensity fog Transferability density fog Transferability 50 Blue 1 AA AAAA AA AA AA 51 Blue 2 AA AA AA AA AA AA 52 Blue 3 AA AA AA AA AA AA 53Blue 4 AA AA AA AA AA AA 54 Blue 5 AA AA AA AA AA AA 55 Blue 6 AA AA AAAA AA AA 56 Blue 7 AA AA AA AA AA AA 57 Yellow 1 AA AA AA AA AA AA 58Yellow 2 AA AA AA AA AA AA 59 Black 1 AA AA AA AA AA AA 60 Black 2 AA AAAA AA AA AA 61 Black 4 AA AA AA AA AA AA 62 Black 6 AA AA AA AA AA AA 63Red 1 AA AA AA AA AA AA 64 Red 2 AA AA AA AA AA AA 65 Red 3 AA AA AA AAAA AA 66 Red 4 AA AA AA AA AA AA 67 Red 7 AA AA AA AA AA AA 68 Black 9AA AA AA AA AA AA 69 Black 10 AA AA AA AA AA AA 70 Black 12 AA AA AA AAAA AA 71 Black 14 AA AA AA AA AA AA 72 Black 15 AA AA AA AA AA AA 73Black 17 AA AA AA AA AA AA 74 Black 18 AA AA AA AA AA AA 75 Black 19 AAAA AA AA AA AA 76 Black 22 AA AA AA AA AA AA Comparative Blue 8 C C C CC C Example 7 Comparative Yellow 8 C C C C C C Example 8 ComparativeBlack 8 B B C B C C Example 9 Comparative Red 8 B B C B C C Example 10Comparative Black 16 B B C C C C Example 11 Comparative Black 24 B B C BC C Example 12

Examples 77 to 91 and Comparative Examples 13 to 15

For carrying out the image formation methods of Examples 77 to 91 andComparative Examples 13 to 15, the toners obtained in Examples 8 to 28and Comparative examples 1 to 3 were used, respectively, as aone-component developer. In addition, for means for forming an image, animage forming apparatus with a commercially available laser beam printerLBP-EX (from Canon Inc.) modified so that it was provided with a reusemechanism and reset as shown in FIG. 3 was used. That is, the imageforming apparatus shown in FIG. 3 is provided with a system in which anon-transferred toner remaining on the photosensitive drum 20 after thetransfer process is scraped off by an elastic blade 22 of a cleaner 21abutting against the photosensitive drum 20, then sent into the cleaner21 by a cleaner roller, passed through a cleaner reuse 23, and returnedto the development device 26 via a hopper 25 by a supply pipe 24 with acarrier screw mounted therein, and the toner collected in this way isreused.

In the image forming apparatus shown in FIG. 3, the surface of thephotosensitive drum 20 is electrically charged by a primary chargeroller 27. A rubber roller (diameter 12 mm, abutment pressure 50 g/cm)coated with a nylon resin and having conductive carbon dispersed thereinwas used for the primary charge roller 27, and an electrostatic latentimage with a dark area potential VD of 31 700 V and a light areapotential VL of −200 V was formed on the electrostatic latent imagecarrier (photosensitive drum 20) by laser exposure (600 dpi, not shown).As a toner carrier, a development sleeve 28 having a roughness degree Raof 1.1 with the surface coated with a resin having a carbon blackdispersed therein was used.

An enlarged sectional view of the principal part of the developmentapparatus for one-component type developers used in Examples 77 to 91and Comparative Examples 13 to 15 is shown in FIG. 4. For conditions fordeveloping electrostatic latent images, the speed of the developmentsleeve 28 was set at a speed 1.1 times as high as the movement speed ofthe surface of the photosensitive drum 20 opposite thereto, and thespace a between the photosensitive drum 20 and the development sleeve 28(between S and D) was 270 μm. For the member for controlling thethickness of the toner, an abutting urethane rubber blade 29 was used.In addition, the set temperature of the heat-fixation apparatus forfixing a toner image was 160° C. Furthermore, for the fixationapparatus, a fixation apparatus shown in FIGS. 5 and 6 was used.

As described above, under the condition of normal temperature and normalhumidity (25° C., 60% RH), images were printed out on up to 30,000sheets at a printout rate of 8 sheets (A4 size) per minute, in acontinuous mode (namely, a mode in which the development device is notstopped, and thereby consumption of the toner is accelerated) supplyingthe toner, and the densities of resulting printout images were measuredto evaluate the durability according to the following criterion. Inaddition, the image from the 10,000 th printout was observed to make anevaluation about image fog according to the following criterion. At thesame time, situations of the components constituting the image formingapparatus after the durability testing were observed to evaluatematching between each component and the above-described toner. Theresults thereof are shown together in Table 5.

[Change in Image Density During Endurance]

Images were printed out on a predetermined number of normal copyingpapers (75 g/m²), and the image density was evaluated according to thelevel at which the density of the image from the final printout wasretained with respect to the density of the initial image. Furthermore,for the measurement of image density, a Macbeth reflective densitometer(from Macbeth Co., Ltd.) was used to measure a density relative to thatof the printout image of a white ground of which original density was0.00.

AA: Excellent (image density from the final printout is 1.40 or greater)

A: Good (image density from the final printout is 1.35 or greater andlower than 1.40)

B: Usable (image density from the final printout is 1.00 or greater andlower than 1.35)

C: Unusable (image density from the final printout is lower than 1.00)

[Image Fog]

Images were printed out on a predetermined number of normal copyingpapers (75 g/m²), and the image fog was evaluated with a solid whiteimage from the final printout. Specifically, the evaluation was made asfollow: the worst value of the reflective density of the white groundafter printing and the average reflective density of the paper beforeprinting, as measured using a reflective densitometer (ReflectometerODEL TC-6DS from Tokyo Denshoku Co., Ltd.), were defined as DS and Dr,respectively, (Ds-Dr) was calculated from these values as a fog level tomake an evaluation according to the following criterion.

AA: Excellent (fog level is 0% or higher and lower than 1.5%)

A: Good (fog level is 1.5% or higher and lower than 3.0%)

B: Usable (fog level is 3.0% or higher and lower than 5.0%)

C: Unusable (fog level is higher than 5.0%)

[Evaluation of Matching with Image Forming Apparatus]

1. Matching with Development Sleeve

After the printout testing was completed, the situation of residualtoners sticking to the surface of the development sleeve and theirinfluence on the printout image were visually evaluated.

AA: Excellent (not observed)

A: Good (almost not observed)

B: Usable (sticking residual toners are observed but the influence onthe image is not significant)

C: Unusable (sticking of residual toners is significant, causingunevenness in the image)

2. Matching with Photosensitive Drum

Occurrences of scars and sticking residual toners on the surface of thephotosensitive drum and their influence on the printout image wereevaluated visually.

AA: Excellent (not observed)

A: Good (slightly observed but no influence on the image)

B: Usable (sticking residual toners and scars are observed but theinfluence on the image is not significant)

C: Unusable (sticking of residual toners is significant, causinglongitudinal striped defects in the image)

3. Matching with Fixation Apparatus

The surface situation of the fixation film was observed, and the resultsof surface characteristics and occurrences of sticking residual tonerswere collectively averaged to evaluate the durability of the film.

(1) Surface Characteristics

Occurrences of scares and flaking on the fixation film were visuallyobserved and evaluated after the printout testing was completed.

AA: Excellent (not observed)

A: Good (almost not observed)

B: Usable

C: Unusable

(2) Situation of Sticking Toners

The situation of residual toners sticking to the surface of the fixationfilm was visually observed and evaluated after the printout testing wascompleted.

AA: Excellent (not observed)

A: Good (almost not observed)

B: Usable

C: Unusable TABLE 5 Evaluation of matching with other Evaluation ofprintout image apparatus Change in image density 10 Fixation duringendurance thousands apparatus 10 30 fogged Development PhotosensitiveSurface Toner Examples Toner Initial Thousand thousands thousands imagessleeve drum characteristic fixation 77 Blue 1 AA AA AA AA AA AA AA AA AA78 Blue 2 AA AA AA AA AA AA AA AA AA 79 Blue 4 AA AA AA AA AA AA AA AAAA 80 Blue 6 AA AA AA AA AA AA AA AA AA 81 Yellow 1 AA AA AA AA AA AA AAAA AA 82 Yellow 2 AA AA AA AA AA AA AA AA AA 83 Yellow 3 AA AA AA AA AAAA AA AA AA 84 Yellow 4 AA AA AA AA AA AA AA AA AA 85 Yellow 5 AA AA AAAA AA AA AA AA AA 86 Yellow 6 AA AA AA AA AA AA AA AA AA 87 Yellow 7 AAAA AA AA AA AA AA AA AA 88 Black 1 AA AA AA AA AA AA AA AA AA 89 Black 2AA AA AA AA AA AA AA AA AA 90 Black 5 AA AA AA AA AA AA AA AA AA 91Black 6 AA AA AA AA AA AA AA AA AA Comparative Blue 8 B C C C C C C C CExample 13 Comparative Yellow 8 B C C C C C C C C Example 14 ComparativeBlack 8 A B C C C C C C C Example 15

Example 92

Printout testing was performed with the blue toner (1) of Example 8 in acontinuous mode (namely, a mode in which the development device is notstopped, and thereby consumption of the toner is accelerated) supplyingthe toner, in the same manner as in Example 77 except that the tonerreuse mechanism of the image forming apparatus of FIG. 3 was removed,and the printout rate was set at the level of 16 sheets (A4 size) perminute. The resulting printout images and the matching with the imageevaluating apparatus used were evaluated for the same items as Examples77 to 91 and Comparative Examples 13 to 15. As a result, satisfactoryresults were obtained for all the items.

Examples 93 to 95

Evaluation was performed in the same manner as in Example 92 except thata blue toner (1) of Example 8 was changed to blue toners (2), (4), and(6) of Examples 9, 11, and 13. As the result, satisfactory results wereobtained for all the items.

1. In a charge control agent for controlling a charge of powder orgranules, wherein the charge control agent comprises apolyhydroxyalkanoate having at least one kind of3-hydroxy-ω-carboxyalkanoic acid unit represented by the chemicalformula (1):

wherein n is an integer selected from the range shown in the samechemical formula; R₁ is an H, Na or K atom, or

and when more than one unit exists, n and R₁ may differ from unit tounit:
 2. The charge control agent according to claim 1, wherein the3-hydroxy-ω-carboxyalkanoic acid unit represented by the chemicalformula (1) includes any one or more selected from the group consistingof: a 3-hydroxy-11-carboxyundecanoic acid unit represented by thechemical formula (2):

wherein R₂ is an H, Na or K atom, or

and when more than one unit exists, R₂ may differ from unit to unit, a3-hydroxy-9-carboxynonanoic acid unit represented by the chemicalformula (3):

wherein R₃ is an H, Na or K atom, or

and when more than one unit exists, R₃ may differ from unit to unit, a3-hydroxy-7-carboxyheptanoic acid unit represented by the chemicalformula (4):

wherein R₄ is an H, Na or K atom, or

and when more than one unit exists, R₄ may differ from unit to unit, anda 3-hydroxy-5-carboxyvaleric acid unit represented by the chemicalformula (5):

wherein R₅ is an H, Na or K atom, or

and when more than one unit exists, R₅ may differ from unit to unit. 3.The charge control agent according to claim 1, characterized bycomprising a polyhydroxyalkanoate that may have, besides at least onekind of 3-hydroxy-ω-carboxyalkanoic acid represented by the chemicalformula (1), a 3-hydroxy-ω-alkanoic acid unit represented by thechemical formula (6):

wherein m is an integer selected from the range shown in the samechemical formula; R₆ comprises a residue having either a phenylstructure or a thienyl structure; and when more than one unit exists, mand R₆ may differ from unit to unit, or a 3-hydroxy-ω-cyclohexylalkanoicacid unit represented by the chemical formula (7):.

wherein R₇ represents a substitute in the cyclohexyl group and is an Hatom, a CN group, an NO₂ group, a halogen atom, a CH₃ group, a C₂H₅group, a C₃H₇ group, a CF₃ group, C₂F₅ group or a C₃F₇ group; and k isan integer selected from the range shown in the same chemical formula,and when more than one unit exists, R₇ and k may differ from unit tounit.
 4. The charge control agent according to claim 1, characterized inthat R₆ in the chemical formula (6), namely a residue having either aphenyl or thienyl structure has at least any one chemical formulaselected from the group consisting of chemical formulae (8), (9), (10),(11), (12), (13), (14), (15), (16), (17) and (18), and when more thanone unit exists, R₆ may differ from unit to unit, wherein the chemicalformula (8) is a group consisting of unsubstituted and substitutedphenyl groups represented by:

wherein R₈ represents a substituent on the aromatic ring and is an Hatom, a halogen atom, a CN group, an NO₂ group, a CH₃ group, a C₂H₅group, a C₃H₇ group, a CH═CH₂ group, COOR₉ (R₉ represents any one of H,Na and K atoms), a CF₃ group, a C₂F₅ group or a C₃F₇ group, and whenmore than one unit exists, R₈ may differ from unit to unit, the chemicalformula (9) is a group consisting of unsubstituted and substitutedphenoxy groups represented by:

wherein R₁₀ represents a substituent on the aromatic ring and is an Hatom, a halogen atom, a CN group, an NO₂ group, a CH₃ group, a C₂H₅group, a C₃H₇ group, an SCH₃ group, a CF₃ group, a C₂F₅ group or a C₃F₇group, and when more than one unit exists, R₁₀ may differ from unit tounit, the chemical formula (10) by a group consisting of unsubstitutedand substituted benzoyl groups represented by:

wherein R₁₁ represents a substituent on the aromatic ring and is an Hatom, a halogen atom, a CN group, an NO₂ group, a CH₃ group, a C₂H₅group, a C₃H₇ group, a CF₃ group, a C₂F₅ group or a C₃F₇ group, and whenmore than one unit exists, R₁₁ may differ from unit to unit, thechemical formula (11) is a group consisting of unsubstituted andsubstituted phenylsulfanyl groups represented by:

wherein R₁₂ represents a substituent on the aromatic ring and is an Hatom, a halogen atom, a CN group, an NO₂ group, a COOR₁₃, an SO₂R₁₄ (R₁₃represents any one of an H atom, an Na atom, a K atom, a CH₃ group and aC₂H₅ group and R₁₄ represents any one of an OH group, an ONa group, anOK group, a halogen atom, an OCH₃ group and OC₂H₅ group), a CH₃ group, aC₂H₅ group, a C₃H₇ group, a (CH₃)₂—CH group or a (CH₃)₃—C group, andwhen more than one unit exists, R₁₂ may differ from unit to unit, thechemical formula (12) is a group consisting of unsubstituted andsubstituted (phenylmethyl)sulfanyl groups represented by:

wherein R₁₅ represents a substituent on the aromatic ring and is an Hatom, a halogen atom, a CN group, an NO₂ group, a COOR₁₆, an SO₂R₁₇ (R₁₆represents any one of an H atom, an Na atom, a K atom, a CH₃ group and aC₂H₅ group and R₁₇ represents any one of an OH group, an ONa group, anOK group, a halogen atom, an OCH₃ group and OC₂H₅ group), a CH₃ group, aC₂H₅ group, a C₃H₇ group, a (CH₃)₂—CH group or a (CH₃)₃—C group, andwhen more than one unit exists, R₁₅ may differ from unit to unit, thechemical formula (13) is a 2-thienyl group represented by:

the chemical formula (14) is a 2-thienylsulfanyl group represented by:

the chemical formula (15) is 2-thienylcarbonyl group represented by:

the chemical formula (16) is a group consisting of unsubstituted andsubstituted phenylsulfinyl groups represented by:

wherein R₁₈ represents a substituent on the aromatic ring and is an Hatom, a halogen atom, a CN group, an NO₂ group, a COOR₁₉, an SO₂R₂₀ (R₁grepresents any one of an H atom, an Na atom, a K atom, a CH₃ group and aC₂H₅ group and R₂₀ represents any one of an OH group, an ONa group, anOK group, a halogen atom, an OCH₃ group and OC₂H₅ group), a CH₃ group, aC₂H₅ group, a C₃H₇ group, a (CH₃)₂—CH group or a (CH₃)₃—C group, andwhen more than one unit exists, R₁₈ may differ from unit to unit, thechemical formula (17) is a group consisting of unsubstituted andsubstituted phenylsulfonyl groups represented by:

wherein R₂₁ represents a substituent on the aromatic ring and is an Hatom, a halogen atom, a CN group, an NO₂ group, a COOR₂₂, an SO₂R₂₃ (R₂₂represents any one of an H atom, an Na atom, a K atom, a CH₃ group and aC₂H₅ group and R₂₃ represents any one of an OH group, an ONa group, anOK group, a halogen atom, an OCH₃ group and OC₂H₅ group), a CH₃ group, aC₂H₅ group, a C₃H₇ group, a (CH₃)₂—CH group or a (CH₃)₃—C group, andwhen more than one unit exists, R₂₁ may differ from unit to unit, thechemical formula (18) is a group of a (phenylmethyl)oxy grouprepresented by:


5. The charge control agent according to claim 1, wherein the powder andgranular material is a toner for developing electrostatic charge images.6. The charge control agent according to claim 1, wherein the numberaverage molecular weight of the polyhydroxyalkanoate is in the range of1,000 to 1,000,000.
 7. In a toner binder used for a toner for developingelectrostatic charge images, characterized by comprising the chargecontrolling agent according to any one of claims 1 to
 6. 8. A toner fordeveloping electrostatic charge images, characterized by comprising atleast a binder resin, a colorant and the charge control agent accordingto any one of claims 1 to
 6. 9. An image forming method, comprising atleast a charging step of charging an electrostatic latent image carrierby applying voltage to a charging member from the outside; anelectrostatic charge image forming step of forming an electrostaticcharge image on the charged electrostatic latent image carrier; adeveloping step of developing the electrostatic charge image with atoner for developing electrostatic charge images to form a toner imageon the electrostatic latent image carrier; a transferring step oftransferring the toner image on the electrostatic latent image carrierto a recording medium; and a fixing step of fixing the toner image onthe recording medium by heat, characterized in that it uses at least abinder resin, a colorant and the charge control agent according to anyone of claims 1 to
 6. 10. The image forming method according to claim 9,characterized in that the transferring step comprises a firsttransferring step of transferring the toner image on the electrostaticlatent image carrier to an intermediate transfer medium; and a secondtransferring step of transferring the toner image on the intermediatetransfer medium to a recording medium.
 11. An image forming apparatus,comprising at least charging means of charging an electrostatic latentimage carrier by applying voltage to a charging member from the outside;electrostatic charge image forming means of forming an electrostaticcharge image on the charged electrostatic latent image carrier;developing means of developing the electrostatic charge image with atoner for developing electrostatic charge images to form a toner imageon the electrostatic latent image carrier; transferring means oftransferring the toner image on the electrostatic latent image carrierto a recording medium; and fixing means of fixing the toner image on therecording medium by heat, characterized in that it uses at least abinder resin, a colorant and the charge control agent according to anyone of claims 1 to
 6. 12. The image forming apparatus according to claim11, characterized in that the transferring means comprises firsttransferring means of transferring the toner image on the electrostaticlatent image carrier to an intermediate transfer medium; and secondtransferring means of transferring the toner image on the intermediatetransfer medium to a recording medium.
 13. A charge controlling method,characterized by comprising the steps of preparing the chargecontrolling agent according to any one of claims 1 to 6; and controllingthe charged state of a toner using the charge controlling agent.